criyle/codenet-compile-errors huggingface dataset:
Language: C++

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <utility>
#include <cstdlib>
#include <cmath>
#include <functional>

#define INF 1000000000000000000
using namespace std;
typedef long long ll;

struct Node {
	ll cost;
	int id;
	bool iso;
};
bool lessNode(const Node &n1, const Node &n2) { 
	if((n1.iso&&n2.iso)||((!n1.iso)&&(!n2.iso))) return n1.cost < n2.cost;
	else if (n2.iso)return true;
	return false;
}

bool used[100010];
int p[100010];
int rankNode[100010];
Node node[100010];
int tree_comp;

int findP(int v) {
	if (v != p[v])return findP(p[v]);
	return v;
}

void unite(int x, int y) {
	int px, py;
	px = findP(x); py = findP(y);
	if (px==py) return;
	if (rankNode[px] < rankNode[py]) {
		p[px] = py;
	}
	else {
		if (rankNode[px] == rankNode[py])rankNode[px]++;
		p[py] = px;
	}
	tree_comp--;
	return;
}

int main(){
	int n,m;
	cin >> n>>m;
	tree_comp = n;
	for (int i = 0; i < n; i++) {
		ll c;
		cin >> c;
		node[i].cost = c;
		node[i].id = i;
		node[i].iso = true;
		p[i] = i;
		rankNode[i] = 0;
		used[i] = false;
	}
	for (int i = 0; i < m; i++) {
		int x, y;
		cin >> x >> y;
		node[x].iso = node[y].iso = false;
		unite(x, y);
	}
	sort(node, node + n, lessNode);
	ll ans = 0LL;
	bool fin = false;
	int j = 0;
	for (int i = 0; i < n-1; i++) {
		if (used[node[i].id])continue;
		int px;
		px = findP(node[i].id);
		fin = true;
		j = max(j, i + 1);
		while (j < n){
			if (node[i].iso&&node[j].iso{ )
				j++; continue;
			}
			if (used[node[j].id]) {
				j++;
				continue;
			}
			int py = findP(node[j].id);
			if (px == py) {
				j++;
				continue;
			}
			unite(px, py);
			ans += node[i].cost + node[j].cost;
			used[node[i].id]=used[node[j].id]=true;
			j++;
			fin = false;
			break;
		}
		if(fin)break;
	}
	if (tree_comp > 1)cout << "Impossible" << endl;
	else cout << ans << endl;

	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:82:53: error: expected ';' before '{' token
   82 |                         if (node[i].iso&&node[j].iso{ )
      |                                                     ^
      |                                                     ;
a.cc:85:25: error: expected primary-expression before 'if'
   85 |                         if (used[node[j].id]) {
      |                         ^~
a.cc:84:26: error: expected ')' before 'if'
   84 |                         }
      |                          ^
      |                          )
   85 |                         if (used[node[j].id]) {
      |                         ~~
a.cc:82:28: note: to match this '('
   82 |                         if (node[i].iso&&node[j].iso{ )
      |                            ^
a.cc:90:35: error: 'py' was not declared in this scope; did you mean 'px'?
   90 |                         if (px == py) {
      |                                   ^~
      |                                   px
a.cc:94:35: error: 'py' was not declared in this scope; did you mean 'px'?
   94 |                         unite(px, py);
      |                                   ^~
      |                                   px
Language: C++

#include <bits/stdc++.h>
// #pragma GCC optimize ("O3")
// #pragma GCC target ("sse4")
 
using namespace std;
 
#define li long long int
#define ld long double
const int MX1=1e5+5;
const int MX2=1e6+5;
const li inf=1e18;
const li mod=1e9+7;
 
li power(li a,li b){li res=1;while(b){if(b%2)res=(res*a)%mod;
a=(a*a)%mod;b/=2;}return res;}
 
li mmi(li a){return power(a,mod-2);}
 
li cntbit(li n){li cnt=0;while(n){n&=(n-1);cnt++;}return cnt;}
 
int n,m;
int a[MX1];
int vis[MX1];
int use[MX1];
int mark[MX1];
int arr[MX1];
int sz[MX1];
int comp;
vector<int> g[MX1];
vector<pair<int,int> > v;

int root(int i){
    while(i!=arr[i]){
        i=arr[arr[i]];
    }
    return i;
}

void unionof(int a,int b){
    int roota=root(a);
    int rootb=root(b);
    if(sz[roota]<sz[rootb]) swap(roota,rootb);
    sz[roota]+=sz[rootb];
    arr[rootb]=roota;
}
 
void dfs(int u){
    vis[u]=1;
    mark[u]=comp;
    for(auto v:g[u]){
        if(!vis[v]){
            dfs(v);
        }
    }
}

bool cmp(pair<int,int> a,pair<int,int> b){
    if(a.first==b.first){
        return sz[a.second]>sz[b.second];
    }
    return a.first<b.first;
}
 
void solve(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        cin>>a[i];
        v.push_back(make_pair(a[i],i));
        arr[i]=i;
        sz[i]=1;
    }
    sort(v.begin(),v.end(),cmp);
    for(int i=0;i<m;i++){
        int x,y;
        cin>>x>>y;
        ++x;
        ++y;
        unionof(x,y);
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for(int i=1;i<=n;i++){
        if(!vis[i]){
            ++comp;
            dfs(i);
        }
    }
    int cnt=1;
    int j=0;
    li ans=0;
    for(int i=0;i<n;){
        j=max(j,i);
        if(use[v[i].second]){
            i++;
            continue;
        }
        while(j<n){
            if(mark[v[i].second]!=mark[v[j].second] and !use[v[i].second] and !use[v[j].second]){
                if(root(v[i].second)==root(v[j].second)){
                    j++;
                    continue;
                }
                ans+=0LL+v[i].first+v[j].first;
                use[v[i].second]=use[v[j].second]=1;
                unionof(v[i].second,v[j].second);
                ++cnt;
                j++;
                break;
            }
            j++;
        }
        if(cnt==comp) break;
        i++;
    }
    if(cnt!=comp){
        cout<<"Impossible";
    }else{
        cout<<ans;
    }
}
 
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    #ifndef ONLINE_JUDGE
    int t=1;
    //cin>>t;
    while(t--){
        solve();
    }
    return 0;
}

Compiler output:
a.cc:125: error: unterminated #ifndef
  125 |     #ifndef ONLINE_JUDGE
Language: C++

#include<bits/stdc++.h>
using namespace std;
int father[100050];
long long cost[100050];
vector<long long>V[100050];
vector<pair<long long,long long> >VV;
vector<long long>P;
int num,edge;
bool cmp(long long a,long long b) {
	return a<b;
}
bool cmp2(pair<long long,long long>a,pair<long long,long long>b) {
	return max(a.first,a.second)>max(b.first,b.second);
}
int seek(int x) {
	return father[x]==x?x:father[x]=seek(father[x]);
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin>>num>>edge;
	for(int i=0; i<num; i++)father[i]=i;
	for(int i=0; i<num; i++)cin>>cost[i];
	for(int i=0; i<edge; i++) {
		int a,b;
		cin>>a>>b;
		int a1=seek(a);
		int a2=seek(b);
		father[a1]=a2;
	}
	set<int>da;
	long long ans=0;
	for(int i=0; i<num; i++) {
		int a1=seek(i);
		V[a1].push_back(cost[i]);
		da.insert(a1);
	}
	int ct=0;
	for(set<int>::iterator it=da.begin(); it!=da.end(); it++) {
		sort(V[*it].begin(),V[*it].end(),cmp);
		if(V[*it].size()==1) {
			ct++;
		}
	}
	int tot=(int)da.size();
	if(tot==1) {
		cout<<0<<endl;
		return 0;
	}
	if(tot==2) {
		for(set<int>::iterator it=da.begin(); it!=da.end(); it++) {
			ans+=V[*it][0];
		}
		cout<<ans<<endl;
		return 0;
	}
	if(tot>=3) {
		if(num<2*(tot-1)) {
			cout<<"Impossible"<<endl;
			return 0;
		} else if(ct>=2) {
			int *pt;
			pt=6;
			for(set<int>::iterator it=da.begin(); it!=da.end(); it++) {
				if(V[*it].size()==1)ans+=V[*it][0];
				else ans=ans+V[*it][0]+V[*it][1];
			}
			ct-=2;
			for(set<int>::iterator it=da.begin(); it!=da.end(); it++) {
				for(int jb=2; jb<(int)V[*it].size(); jb++) {
					P.push_back(V[*it][jb]);
				}
			}
			sort(P.begin(),P.end(),cmp);
			for(int jb=0; jb<ct; jb++) {
				ans+=P[jb];
			}
			cout<<ans<<endl;
			return 0;
		} else if(ct==1) {
			for(set<int>::iterator it=da.begin(); it!=da.end(); it++) {
				ans+=V[*it][0]+V[*it][1];
				VV.push_back(make_pair(V[*it][0],V[*it][1]));
			}
			sort(VV.begin(),VV.end(),cmp2);
			ans=ans-max(VV[0].first,VV[0].second);
			cout<<ans<<endl;
			return 0;
		} else if(ct==0) {
			for(set<int>::iterator it=da.begin(); it!=da.end(); it++) {
				ans+=V[*it][0]+V[*it][1];
				VV.push_back(make_pair(V[*it][0],V[*it][1]));
			}
			sort(VV.begin(),VV.end(),cmp2);
			ans=ans-max(VV[0].first,VV[0].second)-max(VV[1].first,VV[1].second);
			cout<<ans<<endl;
			return 0;
		}
	}
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:63:28: error: invalid conversion from 'int' to 'int*' [-fpermissive]
   63 |                         pt=6;
      |                            ^
      |                            |
      |                            int
Language: C++

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pp;
typedef pair<ll,ll> pll;
void read(int& x){ scanf("%d",&x); }
void read(ll& x){ scanf("%lld",&x); }
template<typename T,typename... Args>
void read(T& a,Args&... b){ read(a); read(b...); }
#define all(x) (x).begin(),(x).end()
#define pb push_back
#define eb emplace_back
#define x first
#define y second
int n, m;
int par[100010];
int r(int x){ return (x==par[x])?x:(par[x]=r(par[x])); }
priority_queue<int> pq[100010];
priority_queue<pp> q;
bool join(int a, int b){
	a=r(a); b=r(b);
	if(a==b) return 0;
	par[a]=b;
	if(pq[a].size()>pq[b].size()) swap(pq[a], pq[b]);
	while(pq[a].size()){
		pq[b].push(pq[a].top()); pq[a].pop();
	}
	return 1;
}
int main()
{
	read(n, m);
	for(int i=0; i<n; ++i){
		par[i]=i;
		int x; read(x);
		pq[i].push(-x);
	}
	for(int i=1; i<=m; ++i){
		int a, b; read(a, b); join(a, b);
	}
	for(int i=0; i<n; ++i) if(par[i]==i) q.emplace(pq[i].top(), i);
	ll ans=0;
	while(q.size() >= 2u){
		int a = q.top().second; q.pop();
		int b = q.top().second; q.pop();
		ans+=pq[a].top()+pq[b].top();
		pq[a].pop(); pq[b].pop();
		join(a, b);
		b=root(b);
		if(pq[b].size()){
			q.emplace(pq[b].top(), b);
		}
	}
	int a=r(0);
	for(int i=1; i<n; ++i) if(r(i)!=a){ puts("Impossible"); return 0; }
	printf("%lld\n", -ans);
	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:49:19: error: 'root' was not declared in this scope
   49 |                 b=root(b);
      |                   ^~~~
Language: C++

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> P;
typedef pair<ll, ll> LP;

#define pb push_back
#define rep(i, a, n) for(int i = (a); i < (n); i++)
#define dep(i, a, n) for(int i = (a); i >= (n); i--)
#define mod (ll)(1e9+7)
#define int ll

__attribute__((constructor))
void initial() {
  cin.tie(0);
  ios::sync_with_stdio(false);
}

struct T {int cost, i;};


bool comp(T& t1, T& t2) {
  return t1.cost < t2.cost;
}

T t[100001];
int par[100001], ran[100001];

int find(int x) {
  if(par[x] == x) return x;
  else return par[x] = find(par[x]);
}

void unite(int x, int y) {
  x = find(x);
  y = find(y);
  if(x == y) return;
  if(ran[x] < ran[y]) {
    par[x] = y;
  }else {
    par[y] = x;
    if(ran[x] == ran[y]) ran[x]++;
  }
}

bool same(int x, int y) {
  return find(x) == find(y);
}

int s[100001], r[100001];

signed main() {
  int v, e, rc = 0;
  cin >> v >> e;
  if((e + 1) * 2 < v) {
    cout << "Impossible" << endl;
    return 0;
  }
  for(int i = 0; i < v; i++) par[i] = i, ran[i] = 0;
  rep(i, 0, v) {
    int a;
    cin >> a;
    t[i] = {a, i};
  }
  rep(i, 0, e) {
    int a, b;
    cin >> a >> b;
    unite(a, b);
  }
  sort(t, t + v, comp);
  int ans = 0;

  rep(i, 0, v) {
    if(s[t[i].i]) continue;
    for(int j = i + 1; j < v; j++) {
      if(s[t[j].i]) {
        if(s[t[j - 1].i]) s[t[j - 1].i]++;
        j += s[t[j]].i;
        continue;
      }
      if(!same(t[i].i, t[j].i)) {
        unite(t[i].i, t[j].i);
        ans += t[i].cost + t[j].cost;
        s[i] = 1, s[j] = 1;
        break;
      }
    }
  }
  cout << ans << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:79:15: error: no match for 'operator[]' (operand types are 'll [100001]' {aka 'long long int [100001]'} and 'T')
   79 |         j += s[t[j]].i;
      |               ^
Language: C++

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> P;
typedef pair<ll, ll> LP;

#define pb push_back
#define rep(i, a, n) for(int i = (a); i < (n); i++)
#define dep(i, a, n) for(int i = (a); i >= (n); i--)
#define mod (ll)(1e9+7)
#define int ll

__attribute__((constructor))
void initial() {
  cin.tie(0);
  ios::sync_with_stdio(false);
}

struct T {int cost, i;};


bool comp(T& t1, T& t2) {
  return t1.cost < t2.cost;
}

T t[100001];
int par[100001], ran[100001];

int find(int x) {
  if(par[x] == x) return x;
  else return par[x] = find(par[x]);
}

void unite(int x, int y) {
  x = find(x);
  y = find(y);
  if(x == y) return;
  if(ran[x] < ran[y]) {
    par[x] = y;
  }else {
    par[y] = x;
    if(ran[x] == ran[y]) ran[x]++;
  }
}

bool same(int x, int y) {
  return find(x) == find(y);
}

int s[100001], r[100001];

signed main() {
  int v, e, rc = 0;
  cin >> v >> e;
  if((e + 1) * 2 < v) {
    cout << "Impossible" << endl;
    return 0;
  }
  for(int i = 0; i < v; i++) par[i] = i, ran[i] = 0;
  rep(i, 0, v) {
    int a;
    cin >> a;
    t[i] = {a, i};
  }
  rep(i, 0, e) {
    int a, b;
    cin >> a >> b;
    unite(a, b);
  }
  sort(t, t + v, comp);
  int ans = 0;

  rep(i, 0, v) {
    if(s[t[i].i]) continue;
    for(int j = i + 1; j < v; j++) {
      if(s[t[j].i]) {
        if(s[t[j - 1].i]) s[t[j - 1].i]++;
        j += s[j].i;
        continue;
      }
      if(!same(t[i].i, t[j].i)) {
        unite(t[i].i, t[j].i);
        ans += t[i].cost + t[j].cost;
        s[i] = 1, s[j] = 1;
        break;
      }
    }
  }
  cout << ans << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:79:19: error: request for member 'i' in 's[j]', which is of non-class type 'll' {aka 'long long int'}
   79 |         j += s[j].i;
      |                   ^
Language: C++

#include <iostream>
#include <vector>
#include <string>
using namespace std;
#define rep(i,a,b) for(int i = a; i < b; i++)
#define inf 1000000000000
typedef long long ll;
typedef long double ld;
typedef vector<ll> vi;
typedef pair<ll,ll> ii;
typedef vector<ii> vii;

vector<vi> edges;
vi _,a,comp,vis,best,rest;
ll cur=0;

void dfs(ll v){
  vis[v] = 1;
  comp[v] = cur;
  rep(i,0,edges[v].size()){
    if (!vis[edges[v][i]]) { dfs(edges[v][i]); }
  }
}

int main(){
  ll N,M,x,y,res=0; cin >> N >> M; edges.assign(N,_); a.assign(N,0); vis.assign(N,0); comp.assign(N,-1);
  rep(i,0,N) cin >> a[i];
  rep(i,0,M) { cin >> x >> y; edges[x].push_back(y); edges[y].push_back(x); }

  rep(i,0,N){
    if (!vis[i]){ dfs(i); cur++; }
  }

  if (2*(cur-1) > N) { cout << "Impossible" << endl; exit(0); }

  best.assign(cur,inf);
  rep(i,0,N) {
    if (best[comp[i]] > a[i]) {
      if (best[comp[i]] != inf) rest.push_back(best[comp[i]]);
      best[comp[i]] = a[i];
    } else { rest.push_back(a[i]); }
  }
  if (cur == 1) {cout << 0 << endl; exit(0);}
  rep(i,0,best.size()) res += best[i];
  sort(rest.begin(), rest.end());
  rep(i,0,cur-2) res += rest[i];
  cout << res << endl;

}


Compiler output:
a.cc: In function 'int main()':
a.cc:45:3: error: 'sort' was not declared in this scope; did you mean 'short'?
   45 |   sort(rest.begin(), rest.end());
      |   ^~~~
      |   short
Language: C++

#include <bits/stdc++.h>
#define re return
#define pb push_back
#define po pop_back
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second
#define ss second.second
#define sf second.first
#define ff first.first
#define fs first.second
#define si size
#define sqrt(x) sqrt(abs(x))
#define mp make_pair
#define pi 3.14159265359
#define er erase
#define in insert
#define em empty
#define ft front
#define fo(i,n) for(i = 0; i < n; i++)
#define ro(i,n) for(i = n - 1; i >= 0; i--)
#define fr(i,j,n) for(i = j; i < n; i++)
#define rf(i,j,n) for(i=n-1;i>=j;i--)
typedef std::vector<int> vi;
typedef std::vector<vi> vvi;
typedef std::pair<int,int> ii;
typedef std::vector<ii> vii;
typedef std::vector<std::string> vs;
typedef double dl;
typedef long double ld;
typedef long long ll;
typedef std::pair<ll, ll> pll;
typedef std::vector<ll> vll;
#define filename ""
using namespace std;
    vector<int> v[(int)1e5];
    int was[(int)1e5];
    int a[(int)1e5];
    vector<int> d[(int)1e5];
    int co[(int)1e5];
    int gwas=0;
bool sss(int x,int y)
{
    if (a[x]==a[y]) re x<y;
    re a[x]<a[y];
}
bool so(vector<int> &x,vector<int> &y)
{
    if (x.size()==y.size()) re x<y;
    re x.size()>y.size();
}
set<int,bool (*)(int,int)> s1(sss),s2(sss);
int f(int x)
{
    int i;
    was[x]=1;
    d[gwas].pb(x);
    co[x]=gwas;
    fo(i,v[x].size())
    {
        if (!was[v[x][i]])
        {
            f(v[x][i]);
        }
    }
}
    vector<int> o;
int main()
{
    /*
	freopen(filename".in","r",stdin);
	freopen(filename".out","w",stdout);
	*/
	/*
	freopen("input.txt","r",stdin);
	freopen("output.txt","w",stdout);
    */
    int n,m,c,t;
    cin>>n>>m;
    int i;
    fo(i,n)
    {
        scanf("%d",&a[i]);
    }
    fo(i,m)
    {
        scanf("%d%d",&c,&t);
        v[t].pb(c);
        v[c].pb(t);
    }
    int b;
    fo(i,n)
    {
        if (!was[i])
        {
            f(i);
            gwas++;
        }
    }
    sort(d,d+gwas,so);
    fo(i,d[0].size())
    {
        s1.in(d[0][i]);
    }
    int j;
    fr(i,1,gwas)
    {
        fo(j,d[i].size())
        {
            s2.in(d[i][j]);
        }
    }
    if (n<(q-1)*2)
    {
        cout<<"Impossible\n";
        re 0;
    }
    ll o=0;
    int r;
    while(!s2.empty())
    {
        o+=a[*s1.begin()];
        o+=a[*s2.begin()];
        r=co[*s2.begin()];
        s1.er(*s1.begin());
        s2.er(*s2.begin());
        fo(j,d[r].size())
        {
            if (s2.find(d[r][j])!=s2.end())
                s1.in(d[r][j]);
            s2.er(d[r][j]);
        }
    }
    cout<<o<<'\n';
    re 0;
}


Compiler output:
a.cc: In function 'int f(int)':
a.cc:66:1: warning: no return statement in function returning non-void [-Wreturn-type]
   66 | }
      | ^
a.cc: In function 'int main()':
a.cc:113:12: error: 'q' was not declared in this scope
  113 |     if (n<(q-1)*2)
      |            ^
Language: C++

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define ll long long
#define f first
#define s second
const ll INF = 1000 * 1000 * 1000;
const ll LINF = (ll)INF * INF;
const ll mod = INF + 7;
const double EPS = 1e-9;
set<pair<ll , ll> > dsu[100000];
ll batya[100000];
ll n , m;
ll a[100000];
set<pair<ll , ll> > lowest;
ll deleted = 0;
ll ans = 0;
void unite(ll u , ll v)
{
	if(dsu[batya[u]].size() > dsu[batya[v]].size())
		swap(u , v);

	//cout << batya[u] << " " << batya[v] << endl;
	ll x = batya[u];
	for(auto it = dsu[x].begin(); it != dsu[x].end(); it++)
	{
		batya[it->second] = batya[v];
		dsu[batya[v]].insert(*it);
	}
	dsu[x].clear();
}
void unite2(pair<ll , ll> u , pair<ll , ll> v)
{
	ans += u.first + v.first;
	ll U = batya[u.second] , V = batya[v.second];
	lowest.erase(u);
	lowest.erase(v);
	if(!dsu[U].size())
	{
		cout << "Impossible";
		exit(0);
	}
	if(!dsu[V].size())
	{
		cout << "Impossible";
		exit(0);
	}
	dsu[U].erase(dsu[U].begin());
	dsu[V].erase(dsu[V].begin());
	if(dsu[V].size() < dsu[U].size())
		swap(U , V);
	for(auto it = dsu[U].begin(); it != dsu[U].end(); it++)
	{
		batya[it->second] = V;
		dsu[V].insert(*it);
	}
	dsu[U].clear();
	if(!dsu[V].size())
	{
		lowest.insert({INF + 1 , V});
	}
	else
	{
		lowest.insert(*dsu[V].begin());
	}
}
ll main()
{
	//freopen("input.txt" , "r" , stdin);
	scanf("%lld %lld" , &n , &m);
	for(ll i = 0; i < n; i++)
	{
		scanf("%lld" , &a[i]);
		batya[i] = i;
		dsu[i].insert({a[i] , i});
	}
	for(ll i = 0; i < m; i++)
	{
		ll u , v;
		scanf("%lld %lld" , &u , &v);
		unite(u , v);
	}
	for(ll i = 0; i < n; i++)
		if(dsu[i].size())
		{
			lowest.insert(*dsu[i].begin());
		}
	deleted = m;
	while(deleted != n - 1)
	{
		if(lowest.size() < 2)
		{
			cout << "Impossible";
			return 0;
		}
		unite2(*lowest.begin() , *(++lowest.begin()));
		deleted++;
	}
	cout << ans;
}



Compiler output:
cc1plus: error: '::main' must return 'int'
Language: C++

#include<iostream>
#include<vector>
#include<stdint>
using namespace std;

const int MAX = 100000;

typedef struct tree {
	int cost;
	bool use;
	int treeNum;
	bool DFSread;
	vector<int> edge;
} Tree;

void setTreeNum(Tree t[], int n, int num) {
//	cout << "木" << n << ":" << num << "番" << endl;
	t[n].treeNum = num;
	t[n].DFSread = true;
	for (int i = 0;i < t[n].edge.size();i ++) {
		if (t[t[n].edge[i]].DFSread) continue;
		setTreeNum(t, t[n].edge[i], num);
	}
	t[n].DFSread = false;
}

int getMinimum(Tree t[], int n) {
	int ret = t[n].cost, tmp;
	t[n].use = true;
	t[n].DFSread = true;
	for (int i = 0;i < t[n].edge.size();i ++) {
		if (t[t[n].edge[i]].DFSread) continue;
		tmp = getMinimum(t, t[n].edge[i]);
		if (ret > tmp) {
			t[n].use = false;
			ret = tmp;
		}
	}
	t[n].DFSread = false;
	return ret;
}

int main() {
	int N, M;
	static pair<int, int> a[MAX]; // コスト記憶用
	cin >> N >> M;
	static Tree t[MAX];
	for (int i = 0;i < N;i ++) {
		cin >> t[i].cost;
		t[i].treeNum = -1;
		t[i].use = false;
		t[i].DFSread = false;
		a[i] = make_pair(t[i].cost, i);
	}
	int x, y;
	for (int i = 0;i < M;i ++) {
		cin >> x >> y;
		t[x].edge.push_back(y);
		t[y].edge.push_back(x);
	}
	
	int num = 0; // 木の数
	int64_t cost = 0; // 最終コスト
	for (int i = 0;i < N;i ++) {
		// 木ごとにナンバリングすることで所属を確定させていくよ！DFSとかで良いかな
		if (t[i].treeNum == -1) { // 未確定木を発見したら
			setTreeNum(t, i, num); // ナンバリングのお時間だ！
			cost += getMinimum(t, i); // そして最小値の頂点を接続用に使うのでコストとして計算
			num ++;
		}
	}
//	cout << "木の数:" << num << endl;
	
	if (num > (N + 2) / 2) {
		cout << "Impossible";
		return 0;
	}
	
	sort(a, a+N); // さっきのコストを記憶してた分がここで生きるよ
	for (int i = 0, c = num - 2;c > 0;i ++) {
		if (t[a[i].second].use == false) { // コスト最小順に見た奴が使われてないなら
			cost += a[i].first; // そのコストを足してしまおう
			c --;
		}
	}
	if (num == 1) cout << 0;
	else cout << cost;
	return 0;
}
/*
まず、impossibleかどうか先に判定してしまおう
これは、森に何本の木があるかで判定できる
木同士を1個つなぐ度に2本の頂点が使用されるので、
N本の木を繋ぐためには2(N-1)個の頂点が必要である
言い換えると、頂点がNならば木の個数は(N+2)/2個以下でないといけない
逆に頂点がNの時木の個数が(N+2)/2個以下ならば必ず1個の木にできる

次に、使用する頂点を選ぶ
選ぶ頂点の数は、木の個数をAとしたときに2(A-1)個であり、しかもそれは全ての木から最低でも1個は選ぶ必要がある
逆に、全ての木から1個ずつ選べば後は一番コストの小さい頂点から順に選べば良いことが分かる

全ての木からまず1個ずつの頂点を選び、次にA-2個の任意頂点を選べば良いわけだ
当然だが頂点はコスト最小順かつまだ使われていない奴
後は分かるな？

あ、注意点
木の数が1本の時のみ、全ての木から1個ずつの～の下りが不要になる
よってこの時は0返しておけばいい
*/

Compiler output:
a.cc:3:9: fatal error: stdint: No such file or directory
    3 | #include<stdint>
      |         ^~~~~~~~
compilation terminated.
Language: C++

#include <cstdio>
#include <iostream>
#include <cmath>
#include <cstring>
#include <sstream>
#include <algorithm>
#include <cstdlib>
#include <map>
#include <queue>
#include <utility>
#include <vector>
#include <set>
#include <memory.h>
#include <iomanip>
#include <bitset>
#include <list>
#include <stack>
#include <deque>

using namespace std;

#define mod 1000000007

class UF
{
private:
	vector<long long int> parent;

public:
	UF(long long int n)
	{
		parent = vector<long long int>(n + 1, -1);
	}

	long long int getparent(long long int x)
	{
		if(parent[x] == -1) return x;
		else return parent[x] = getparent(parent[x]);
	}

	void unite(long long int x, long long int y)
	{
		x = getparent(x);
		y = getparent(y);
		if(x == y) return;
		if(x > y) swap(x, y);
		parent[y] = x;
	}
};

int main()
{
	long long int n, m;
	cin >> n >> m;
	UF uf(n);
	priority_queue<pair<long long int ,long long int> > qu;
	for(int i = 0; i < n; i++){
		long long int a;
		cin >> a;
		qu.push(make_pair(-a, i));
	}
	for(int i = 0; i < m; i++){
		long long int x, y;
		cin >> x >> y;
		uf.unite(x, y);
	}
	priority_queue<pair<long long int, long long int> > tmpqu;
	long long int ans = 0;
	while(!qu.empty()){
		pair<long long int, long long int> f;
		if(tmpqu.empty()){
			f = qu.front();
			qu.pop();
		} else {
			f = tmpqu.front();
			tmpqu.pop();
		}
		while(!qu.empty()){
			pair<long long int, long long int> tmp = qu.top();
			qu.pop();
			if(uf.getparent(tmp.second) == uf.getparent(f.second)){
				tmpqu.push(tmp);
			} else {
				uf.unite(tmp.second, f.second);
				ans += -f.first + -tmp.first;
				break;
			}
		}
	}
	for(int i = 0; i < n - 1; i++){
		if(uf.getparent(i) != uf.getparent(i + 1)){
			cout << "Impossible" << endl;
			return 0;
		}
	}
	cout << ans << endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:72:32: error: 'class std::priority_queue<std::pair<long long int, long long int> >' has no member named 'front'
   72 |                         f = qu.front();
      |                                ^~~~~
a.cc:75:35: error: 'class std::priority_queue<std::pair<long long int, long long int> >' has no member named 'front'
   75 |                         f = tmpqu.front();
      |                                   ^~~~~
Language: C++

#include<iostream>
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<algorithm>
#include<math.h>
#include<queue>
#include<vector>
#include<set>
#include<map>
#include<stack>
const int maxn =1e5+5;
const double INF=0xfffff;
using namespace std;
int pre[maxn];
int val[maxn];
int num[maxn];//集合的元素数
int minn[maxn];//集合内最大值
map<int,int> mm;
int book[maxn];
struct node
{
    int x, y;
    friend bool operator < (node a, node b)
    {
        return a.x > b.x;//结构体中，x小的优先级高
    }
};
priority_queue<node>q;
int find(int x)
{
	if(pre[x]!=x)
		pre[x]=find(pre[x]);
		return pre[x];
}
void join(int x,int y)
{
	int p,q;
	p=find(x);
	q=find(y);
	if(p!=q)
		{
			pre[p]=q;
		}
	return ;
}
int main()
{
   int n,m;
   int cnt=0;
   int pp=0;
   int x,y,z;
   int sum=0;
  ll ans=0;
   int i;
  scanf("%d%d",&n,&m);
  for(int i=0;i<n;i++)
  {
      cin>>val[i];
  }
   	for(i=0;i<=n;i++)
   	{
   		pre[i]=i;
   	}
   	while(m--)
   	{
   	   scanf("%d%d",&x,&y);
	   	join(x,y);
   	}
   	for(int i=0;i<n;i++)
    {
         int tmp=find(i);
         if(book[tmp]==0)
         {
             book[tmp]=1;
             cnt++;
         }
         node pp;
        pp.x=val[i];
        pp.y=tmp;
        q.push(pp);
    }
    while(!q.empty())
    {
        int a=q.top().x;
        int b=q.top().y;
        q.pop();
        if(mm[b]<cnt-1&&sum<(cnt-1)*2)
        {
            sum++;
            mm[b]++;
            ans+=a;
        }
        if(sum==(cnt-1)*2)
            break;
    }
    if(sum<(cnt-1)*2)
        cout<<"Impossible"<<endl;
    else
    cout<<ans<<endl;
   return 0;
 }


Compiler output:
a.cc: In function 'int main()':
a.cc:54:3: error: 'll' was not declared in this scope
   54 |   ll ans=0;
      |   ^~
a.cc:92:13: error: 'ans' was not declared in this scope; did you mean 'abs'?
   92 |             ans+=a;
      |             ^~~
      |             abs
a.cc:100:11: error: 'ans' was not declared in this scope; did you mean 'abs'?
  100 |     cout<<ans<<endl;
      |           ^~~
      |           abs
Language: C++

#include <cstdio>
#include <string>
#include <iostream>
#include <cstdlib>
#include <algorithm>

#define MAXN 100009


std::vector < int > a[MAXN];
int t[MAXN], val[MAXN], v[MAXN];

int sef(int x) {
    if (t[x] == x) return x;
    else return t[x] = sef(t[x]);
}

int main() {
    int n, m;
    scanf("%d%d", &n, &m);

    for (int i = 1; i <= n; i++) {
        t[i] = i;
        scanf("%d", &val[i]);
    }

    for (int i = 1; i <= m; i++) {
        int x, y;
        scanf("%d%d", &x, &y);
        x++;
        y++;

        t[sef(x)] = sef(y);
    }

    for (int i = 1; i <= n; i++)
        a[sef(i)].push_back(val[i]);

    long long sum = 0;
    int cnt = 0;
    for (int i = 1; i <= n; i++) {
        if (t[i] == i) {
            std::sort(a[i].begin(), a[i].end());
            sum += a[i][0];
            cnt++;
            for (int j = 1; j < (int)a[i].size(); j++)
                v[++v[0]] = a[i][j];
        }
    }

    bool ok = 1;
    if (cnt == 1)
        sum = 0;
    if (v[0] < cnt - 2)
        ok = 0;
    else {
        std::sort(v + 1, v + v[0] + 1);
        for (int i = 1; i <= cnt - 2; i++)
            sum += v[i];
    }

    if (ok == 0)
        printf("Impossible\n");
    else
        printf("%lld\n", sum);

    return 0;
}


Compiler output:
a.cc:10:6: error: 'vector' in namespace 'std' does not name a template type
   10 | std::vector < int > a[MAXN];
      |      ^~~~~~
a.cc:6:1: note: 'std::vector' is defined in header '<vector>'; this is probably fixable by adding '#include <vector>'
    5 | #include <algorithm>
  +++ |+#include <vector>
    6 | 
a.cc: In function 'int main()':
a.cc:37:9: error: 'a' was not declared in this scope
   37 |         a[sef(i)].push_back(val[i]);
      |         ^
a.cc:43:23: error: 'a' was not declared in this scope
   43 |             std::sort(a[i].begin(), a[i].end());
      |                       ^
Language: C++

#include <bits/stdc++.h>
#define MOD 1000000007LL
using namespace std;
typedef long long ll;
typedef pair<ll,int> P;

int n,m;
ll a[100001];
vector<int> G[100001];
int cmp[100001];

struct quickfind{
	int par[200005];
	priority_queue<ll,vector<ll>,greater<ll> > qi[200005];
	quickfind(){
	}
	void init(int n){
		for(int i=0;i<n;i++){
			par[i]=i;
		}
	}
	int find(int x){
		if(par[x]==x)return x;
		return par[x]=find(par[x]);
	}

	void insert(int x,int y){
		qi[x].push(y);
	}

	void unite(int x,int y){
		x=find(x);
		y=find(y);
		if(x==y)return;
		if(qi[x].size()<qi[y].size()){
			par[x]=y;
			while(qi[x].size()){
				ll v=qi[x].top();
				qi[x].pop();
				qi[y].push(v);
			}
		}else{
			par[y]=x;
			while(qi[y].size()){
				ll v=qi[y].top();
				qi[y].pop();
				qi[x].push(v);
			}
		}
	}

	bool same(int x,int y){
		return find(x)==find(y);
	}
};

quickfind qui;

void dfs(int v,int c){
	cmp[v]=c;
	qui.qi[c].push(a[v]);
	for(int i=0;i<G[v].size();i++){
		if(cmp[G[v][i]]==-1){
			dfs(G[v][i],c);
		}
	}
}

int main(void){
	scanf("%d%d",&n,&m);
	for(int i=0;i<n;i++){
		scanf("%lld",&a[i]);
	}
	for(int i=0;i<m;i++){
		int u,v;
		scanf("%d%d",&u,&v);
		G[u].push_back(v);
		G[v].push_back(u);
	}
	memset(cmp,-1,sizeof(cmp));
	int cnt=0;
	for(int i=0;i<n;i++){
		if(cmp[i]==-1)dfs(i,cnt++);
	}
	if(cnt==1){
		puts("0");
		return 0;
	}
	priority_queue<P,vector<P>,greater<P> > p1;
	priority_queue<P,vector<P>,greater<P> > p2;
	for(int i=0;i<cnt;i++){
		if(qui.qi[i].size()>=2)p1.push(P(qui.qi[i].top(),i));
		else{
			p2.push(P(qui.qi[i].top(),i));
		}
	}
	qui.init(cnt);
	ll ans=0;
	for(int i=0;i<cnt-1;i++){
		if(p1.size()==0){
			if(i!=(cnt-2)){
				puts("Impossible");
				return 0;
			}
			P v1=p2.top();
			p2.pop();
			P v2=p2.top();
			ans+=v1.first+v2.first;
		}else{
			P v1=p1.top();
			p1.pop();
			P v2;
			if(p1s.size()){
				v2=p1.top();
				p1.pop();
			}else{
				v2=p2.top();
				p2.pop();
			}
			qui.qi[v1.second].pop();
			qui.qi[v2.second].pop();
			ans+=v1.first+v2.first;
			qui.unite(v1.second,v2.second);
			int ne=qui.find(v1.second);
			if(qui.qi[ne].size()==1){
				p2.push(P(qui.qi[ne].top(),ne));
			}else{
				p1.push(P(qui.qi[ne].top(),ne));
			}
		}
	}
	printf("%lld\n",ans);
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:113:28: error: 'p1s' was not declared in this scope; did you mean 'p1'?
  113 |                         if(p1s.size()){
      |                            ^~~
      |                            p1
Language: C++


//be naame khodaa

#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <string>
#include <cstdio>
#include <algorithm>
#include <set>
#include <cassert>
#include <iomanip>
#include <cstring>
#include <sstream>
#define fi first
#define se second
#define pb push_back
#define mp make_pair

using namespace std;

typedef long long ll;
typedef pair <int, int> pii;

int in(){ int x; scanf("%d", &x); return x; }

const int maxn = 100 * 1000 + 5;

int a[maxn];
int par[maxn];
vector <int> v[maxn];
vector <int> V;

int find(int x){ return (par[x] < 0 ? x : par[x] = find(par[x])); }

void merge(int x, int y){
	x = find(x), y = find(y);
	if (x == y) return;
	if (par[x] < par[y]) swap(x, y);
	par[y] += par[x];
	par[x] = y;
}

int main()
{
	ios::sync_with_stdio(false);
	int n = in(), m = in();
	for (int i = 0; i < n; i++){
		a[i] = in();
		par[i] = -1;
	}
	for (int i = 0; i < m; i++){
		int x = in(), y = in();
		merge(x, y);
	}
	for (int i = 0; i < n; i++)
		v[find(i)].pb(a[i]);
	ll cur = 0;
	int cnt = 0;
	for (int i = 0; i < n; i++){
		if (v[i].size() == 0) continue;
		sort(v[i].begin(), v[i].end());
		cnt++;
		cur += v[i][0];
		for (int j = 1; j < v[i].size(); j++)
			V.pb(v[i][j]);
	}
	if (cnt == 1){
		cout << 0 << endl;
		return 0;
	}
	if (V.size() < cnt-2)
		return (cout << "Impossible\n");
	sort(V.begin(), V.end());
	for (int i = 0; i < cnt-2; i++)
		cur += V[i];
	cout << cur << endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:76:30: error: cannot convert 'std::basic_ostream<char>' to 'int' in return
   76 |                 return (cout << "Impossible\n");
      |                        ~~~~~~^~~~~~~~~~~~~~~~~~
      |                              |
      |                              std::basic_ostream<char>
Language: C++

#include <algorithm>
#include <cassert>
#include <cstring>
#include <iostream>
#include <vector>

using namespace std;

#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define TRACE(x) cout << #x << " = " << x << endl
#define _ << " _ " <<

typedef long long llint;

const int MAX = 100100;

vector<int> E[MAX];
int a[MAX];

vector<int> comp[MAX];
bool bio[MAX];

void dfs(int x, int c) {
  comp[c].push_back(x);
  bio[x] = true;

  for (int y: E[x]) {
    if (!bio[y]) {
      dfs(y, c);
    }
  }
}

int main(void) {
  int N, M;
  scanf("%d %d", &N, &M);
  REP(i, N) scanf("%d", &a[i]);
  REP(i, M) {
    int a, b;
    scanf("%d %d", &a, &b);
    E[a].push_back(b);
    E[b].push_back(a);
  }

  if (N == 1) {
    puts("0");
    return 0;
  }


  int nc = 0;
  REP(i, N) {
    if (!bio[i]) {
      dfs(i, nc++);
    }
  }

  vector<int> rem;
  llint ret = 0;
  REP(i, nc) {
    vector<int> v;
    for (int x: comp[i]) v.push_back(a[x]);

    sort(v.begin(), v.end());
    ret += v[0];
    for (int i = 1; i < (int)v.size(); ++i) {
      rem.push_back(v[i]);
    }
  }

  sort(rem.begin(), rem.end());
  if ((int)rem.size() < (nc-2)) {
    puts("Impossible");
  } else {
    ret += accumulate(rem.begin(), rem.begin() + nc-2, 0LL);
    printf("%lld\n", ret);
  }
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:76:12: error: 'accumulate' was not declared in this scope
   76 |     ret += accumulate(rem.begin(), rem.begin() + nc-2, 0LL);
      |            ^~~~~~~~~~
Language: Java

import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.PrimitiveIterator;
import java.util.PriorityQueue;
import java.util.Scanner;
import java.util.stream.IntStream;
import java.util.stream.Stream;

class Main{
	static class UF{
		public int[] uni;
		public UF(int size){
			uni=new int[size];
			Arrays.fill(uni,-1);
		}
		public int root(int t){
			if(uni[t]<0)
				return t;
			return uni[t]=root(uni[t]);
		}
		public boolean connect(int p,int c){
			p=root(p);
			c=root(c);
			if(p==c)
				return false;
			if(uni[p]>uni[c]){
				final int buf=c;
				c=p;
				p=buf;
			}
			uni[p]+=uni[c];
			uni[c]=p;
			return true;
		}
		public boolean isConnected(int a,int b){
			return root(a)==root(b);
		}
		public int groupSize(int t){
			return -uni[root(t)];
		}
	}

	class E{
		int treeno,cost;
	}

	private void solve(){
		int n=gInt();
		int[] cost=ints(n).toArray();
		UF treediv=new UF(n);
		for(int v:rep(gInt())) {
			int a=gInt(),b=gInt();
			treediv.connect(Math.min(a,b),Math.max(a,b));
		}
		HashMap<Integer,PriorityQueue<Integer>>m=new HashMap<>();
		for(int i=0;i<n;++i) {
			m.computeIfAbsent(treediv.root(i),PriorityQueue::new)
			.add(null)
		}
	}

	public static void main(String[] $){
		new Main().solve();
	}

	static Scanner s=new Scanner(System.in);


	static int gInt(){
		return s.nextInt();
	}
	static long gLong(){
		return s.nextLong();
	}
	static long gDouble(){
		return s.nextLong();
	}


	static Range rep(int i){
		return new Range(i);
	}
	static Range rep(int f,int t,int d){
		return new Range(f,t,d);
	}
	static Range rep(int f,int t){
		return rep(f,t,1);
	}
	static Range rrep(int f,int t){
		return rep(f,t,-1);
	}

	static class Range implements Iterable<Integer>,PrimitiveIterator.OfInt{

		int to,cur,d;

		Range(int from,int to,int d){
			this.cur=from-d;
			this.to=to;
			this.d=d;
		}

		Range(int n){
			this(0,n-1,1);
		}

		@Override
		public Iterator<Integer> iterator(){
			return this;
		}

		@Override
		public boolean hasNext(){
			return cur+d==to||(cur!=to&&(cur<to==cur+d<to));
		}

		@Override
		public int nextInt(){
			return cur+=d;
		}
	}


	static IntStream REPS(int v){
		return IntStream.range(0,v);
	}

	static IntStream REPS(int l,int r){
		return IntStream.rangeClosed(l,r);
	}


	static IntStream ints(int n){
		return REPS(n).map(i->gInt());
	}

	static Stream<String> strs(int n){
		return REPS(n).mapToObj(i->s.next());
	}

}

Compiler output:
Main.java:59: error: ';' expected
			.add(null)
			          ^
1 error
Language: C++

#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define repr(i, n) for (int i = (n); i >= 0; --i)
#define FOR(i, m, n) for (int i = (m); i < (n); ++i)
#define FORR(i, m, n) for (int i = (m); i >= (n); --i)
#define equals(a, b) (fabs((a) - (b)) < EPS)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
const ll mod = 1000000007;
//const ll mod = 998244353;
const int inf = 1e9 + 10;
const ll INF = 1e18;
const ld EPS = 1e-10;
const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }

vector<int> G[100100];
int d[100100];
int root = 0;

void dfs(int v, int p) {
  for (int u: G[v]) {
    if (u == p) continue;
    d[u] = d[v] + 1;
    dfs(u, v);
  }
}

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout << fixed << setprecision(25);

  int n;
  cin >> n;
  rep(i, n - 1) {
    int a, b;
    cin >> a >> b;
    G[a].push_back(b);
    G[b].push_back(a);
  }

  int ans = 0;
  rep(i, n) chmax(ans, G[i].size() - 1);
  cout << ans << '\n';


  




  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:48:18: error: no matching function for call to 'chmax(int&, std::vector<int>::size_type)'
   48 |   rep(i, n) chmax(ans, G[i].size() - 1);
      |             ~~~~~^~~~~~~~~~~~~~~~~~~~~~
a.cc:18:24: note: candidate: 'template<class T> bool chmax(T&, const T&)'
   18 | template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
      |                        ^~~~~
a.cc:18:24: note:   template argument deduction/substitution failed:
a.cc:48:18: note:   deduced conflicting types for parameter 'const T' ('int' and 'std::vector<int>::size_type' {aka 'long unsigned int'})
   48 |   rep(i, n) chmax(ans, G[i].size() - 1);
      |             ~~~~~^~~~~~~~~~~~~~~~~~~~~~
Language: C++

#include <iostream>
#include <vector>
#include <queue>
using namespace std;
typedef pair<int, int> P;

struct Graph
{
    int n;
    vector<vector<int>> g;
    
    Graph(int n) : n(n){
        g.resize(n);
    }
    
    void init(int n_){
        n = n_;
        g.resize(n_);
    }
    
    void add_edge(int from, int to){
        g[from].push_back(to);
    }
};

struct Tree	//create tree(directed) from graph(undirected)
{
    int n;
    int root;
    vector<vector<int>> t;
    vector<int> par;
    vector<int> dpt;
    
    void init(Graph &g, int root_){
        n = g.n;
        root = root_;
        t.resize(n);
        par.resize(n);
        dpt.resize(n);
        fill(dpt.begin(), dpt.end(), -1);
        queue<int> que;
        par[root] = -1;
        dpt[root] = 0;
        que.push(root);
        while(que.size()){
            int pa = que.front();
            que.pop();
            for(int ch : g.g[pa]){
                if(dpt[ch] == -1){
                    t[pa].push_back(ch);
                    par[ch] = pa;
                    dpt[ch] = dpt[pa] + 1;
                    que.push(ch);
                }
            }
        }
    }

    Tree(){}
    
    Tree(Graph &g, int root_){
        init(g, root_);
    }
};

int main()
{
    int n;
    cin >> n;
    Graph g(n);
    for(int i = 0; i < n - 1; i++){
        int a, b;
        cin >> a >> b;
        g.add_edge(a, b);
        g.add_edge(b, a);
    }
    if(n == 2){
        cout << 1 << endl;
        return 0;
    }
    Tree t;
    for(int i = 0; i < n; i++){
        if((int)g.g[i].size() >= 2){
            t.init(g, i);
            break;
        }
    }
    vector<P> v(n);
    for(int i = 0; i < n; i++) v[i] = P(t.dpt[i], i);
    sort(v.begin(), v.end(), greater<P>());
    bool b[100002];
    int ans = 0;
    for(int i = 0; i < n; i++){
        int u = v[i].second;
        if((int)t.t[u].size() == 0) b[u] = true;
        else if((int)t.t[u].size() == 1){
            if(b[t.t[u][0]]) b[u] = true;
            else b[u] = false;
        }
        else{
            int s = 0;
            for(int v : t.t[u]) if(b[v]) s++;
            ans += max(0, s - 1);
            b[u] = false;
        }
    }
    cout << ans << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:90:5: error: 'sort' was not declared in this scope; did you mean 'short'?
   90 |     sort(v.begin(), v.end(), greater<P>());
      |     ^~~~
      |     short
Language: C++

#pragma gcc optimize("Ofast")

#include "bits/stdc++.h"
using namespace std;
typedef int64_t lld;
typedef pair<int,int> pii;
typedef pair<lld,lld> pll;
typedef pair<int,pll> pip;
typedef pair<pll,int> ppi;
typedef pair<lld,pll> plp;
typedef pair<pll,lld> ppl;
typedef pair<pll,pll> ppp;
template<typename T>
using maxHeap = priority_queue<T,vector<T>,less<T>>;
template<typename T>
using minHeap = priority_queue<T,vector<T>,greater<T>>;
#define ff first
#define ss second
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define endl '\n'
#define jizz cin.tie(0);cout.tie(0);ios::sync_with_stdio(0);
inline void input(int &_x) {
    _x = 0;
    int _tmp = 1; char _tc = getchar();
    while((_tc < '0' || _tc > '9') && _tc != '-') _tc = getchar();
    if(_tc == '-') _tc = getchar(), _tmp = -1;
    while(_tc >= '0' && _tc <= '9') _x = _x*10+(_tc-48), _tc = getchar();
    _x *= _tmp;
}
inline void output(int _x) {
    char _buff[20]; int _f = 0;
    if(_x == 0)putchar('0');
    while(_x > 0)
    {
        _buff[_f++] = _x%10+'0';
        _x /= 10;
    }
    for(_f-=1; _f >= 0; _f--)
        putchar(_buff[_f]);
    putchar('\n');
}
template<typename Iter>
ostream& _out(ostream &s, Iter b, Iter e) {
    s<<"[";
    for ( auto it=b; it!=e; it++ ) s<<(it==b?"":" ")<<*it;
    s<<"]";
    return s;
}
template<class T1,class T2>
ostream& operator<<(ostream& out, pair<T1,T2> p) {
    return out << '(' << p.first << ", " << p.second << ')';
}
template<typename T>
ostream& operator <<( ostream &s, const vector<T> &c ) {
     return _out(s,c.begin(),c.end());
 }
#ifdef erd1
    #define pprint(x) cerr<<__PRETTY_FUNCTION__<<":"<<__LINE__<<" - "<<(#x)<<"="<<(x)<<endl
#else
    #define pprint(x)
#endif

// code starts here
vector<vector<int>> G;
pii dfs(int i, int p){
    int zcnt = 0, ans = 0, nu = false, cnt = 0, nn;
    for(auto x: G[i])
        if(x != p){
            cnt++;
            pii d = dfs(x, i);
            if(!d.ff)zcnt++;
            ans+=d.ff;
            if(d.ss)nu = true, nn = d.ff;
        }
    ans += max(0, zcnt-1);
    if(nu)nu = ans==nn;
    if(!cnt)nu = true;
    if(i==p && nu)ans++;
    //cout << i << " " << ans << endl;
    return {ans, nu || zcnt!=0};
}
int S(pii p){ return p.ff + p.ss; }
signed main(){
    int n;
    cin >> n;
    G.resize(n);
    for(int i = 1; i < n; i++){
        int a, b;
        cin >> a >> b;
        G[a].pb(b);
        G[b].pb(a);
    }
    for(int i = 0; i < n; i++)
        if(G[i].size() == 1)return cout << dfs(i, i).ff << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:95:57: error: cannot convert 'std::basic_ostream<char>' to 'int' in return
   95 |         if(G[i].size() == 1)return cout << dfs(i, i).ff << endl;
      |                                                         ^
      |                                                         |
      |                                                         std::basic_ostream<char>
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main(){
  int n;cin>>n;
  vector<int> edge[n];
  for(int i=1;i<n;i++){
    int u,v;cin>>u>>v;
    edge[u].push_back(v);
    edge[v].push_back(u);
  }
  vector<int> parent(n,-1),son[n];
  queue<int> que;
  que.push(0);
  while(que.size()){
    int p=que.front();que.pop();
    for(int q:edge[p]){
      if(parent[p]==q)continue;
      parent[q]=p;
      son[p].push_back(q);
      que.push(q);
    }
  }
  vector<int> res(n),ant(n,0);
  int ans=0;
  for(int i=0;i<n;i++){
    res[i]=son[i].size();
    if(!res[i])que.push(i);
  }
  while(que.size()){
    int p=que.front();que.pop();//cout<<"P"<<p<<endl;
    int cnt=0;
    for(int q:son[p]){
      if(ant[q])ant[p]=1;
      else cnt++;
    }
    if(cnt>1){
      for(int q:son[p]){
        if(!ant[q])ant[q]=1,ans++,cnt--;
        if(cnt==1)break;
      }
      ant[p]=1;
    }
    if(~parent[p])if(--res[parent[p]]==0)que.push(parent[p]);
  }
  int f=0;
  for(int p:son[q])
    for(int q:son[p])
      if(!ant[q])
        f=1;
  ans+=f;
  //for(int i=0;i<n;i++)cout<<ant[i]<<" ";cout<<endl;
  cout<<max(ans,1)<<endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:47:17: error: 'q' was not declared in this scope
   47 |   for(int p:son[q])
      |                 ^
Language: C++

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair <ll, ll> pii;
const int N = 1e5 + 10, inf = 1e9;

ll deg[N], n, dp[N];
vector <int> adj[N];

void dfs(int v, int p = -1) {
	ll ans = 0;
	int cnt = 0;
	for (auto u : adj[v]) {
		if(u == p) 	continue;
		dfs(u, v);
		dp[v] += dp[u];
		if(dp[u] == 0)
			cnt++;
	}
	if(cnt)
		dp[v] += cnt - 1;
}

int main() {
	// task
	ios_base::sync_with_stdio(0), cin.tie(0);
	cin >> n;
	for (int i = 0; i < n - 1; i++) {
		int v, u;
		cin >> v >> u;
		adj[v].push_back(u), adj[u].push_back(v);
		deg[v]++, deg[u]++;
	}
	ll root = inf;
	for (int i = 0; i < n; i++) {
		if(deg[i] > 2)
			root = min(root, i);
	}
	if(root == inf) {
		cout << 1 << "\n";
	}
	else {
		dfs(root);
		cout << dp[root] << "\n";
	}
}

Compiler output:
a.cc: In function 'int main()':
a.cc:38:35: error: no matching function for call to 'min(ll&, int&)'
   38 |                         root = min(root, i);
      |                                ~~~^~~~~~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:233:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::min(const _Tp&, const _Tp&)'
  233 |     min(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:233:5: note:   template argument deduction/substitution failed:
a.cc:38:35: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'int')
   38 |                         root = min(root, i);
      |                                ~~~^~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:281:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::min(const _Tp&, const _Tp&, _Compare)'
  281 |     min(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:281:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5686:5: note: candidate: 'template<class _Tp> constexpr _Tp std::min(initializer_list<_Tp>)'
 5686 |     min(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5686:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5696:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::min(initializer_list<_Tp>, _Compare)'
 5696 |     min(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5696:5: note:   template argument deduction/substitution failed:
a.cc:38:35: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   38 |                         root = min(root, i);
      |                                ~~~^~~~~~~~~