Problem p02698 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set                                                            \\
  tree<int, null_type, less<int>, rb_tree_tag,                                 \\
       tree_order_statistics_node_update>
#define FAST                                                                   \\
  std::ios_base::sync_with_stdio(false);                                       \\
  cin.tie(0);                                                                  \\
  cout.tie(0);
#define pi acos(-1)
#define mp make_pair
#define pb push_back
#define ALL(v) v.begin(), v.end()
#define SORT(v) sort(ALL(v))
#define REVERSE(v) reverse(ALL(v))
#define F first
#define S second
#define ppb pop_back
#define GCD(m, n) __gcd(m, n)
#define LCM(m, n) (m * n) / GCD(m, n)
#define inputarr(a, n)                                                         \\
  for (int i = 0; i < n; ++i)                                                  \\
  cin >> a[i]
#define initarr(a, n, x)                                                       \\
  for (int i = 0; i < n; ++i)                                                  \\
  a[i] = x
#define rep(i, a, n) for (int i = a; i < n; i++)
#define repe(i, a, n) for (int i = a; i <= n; i++)
#define rev(i, a, b) for (int i = a; i >= b; i--)

#define int long long  ////////////
#define MOD 1000000007 ////////
#define POD 998244353  ////////
// define ll long long
#define ld long double

typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<vvvi> vvvvi;
typedef vector<char> vc;
typedef vector<vc> vvc;
typedef vector<vvc> vvvc;
typedef vector<pii> vpii;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef map<int, int> mii;
typedef unordered_map<int, int> umii;
typedef map<char, int> mci;

#define itv for (auto it = v.begin(); it != v.end(); ++it)
#define present(container, element) (container.find(element) != container.end())
#define cpresent(container, element)                                           \\
  (find(ALL(container), element) != container.end())
// #define invect(data,n,commands) for(int i = 0;i<n;i++){int
// tmp;cin>>tmp;data.pb(tmp);commands} #define inset(data,n,commands) for(int i
// = 0;i<n;i++){int tmp;cin>>tmp;data.insert(tmp);commands} #define trav(a, x)
// for(auto& a : x) #define display(x) trav(a,x) cout<<a<<" ";cout<<endl

#define bs binary_search
#define lb(v, val) lower_bound(ALL(v), val)
#define ub(v, val) upper_bound(ALL(v), val)
#define Max(x, y, z) max(x, max(y, z))
#define Min(x, y, z) min(x, min(y, z))
#define maxc(v) *max_element(ALL(v))
#define minc(v) *min_element(ALL(v))
/*
#define dbg1(a) cout<<" *"<<a<<" ";
#define dbg2(a,b) cout<<" *"<<a<<" **"<<b<<" "     /////
#define dbg cout<<"move"
*/

#define vin(v, n)                                                              \\
  ;                                                                            \\
  vi v(n);                                                                     \\
  rep(i, 0, n) cin >> v[i];
#define dbg cerr << "At line " << __LINE__ << " move " << nl
#define dbg1(x) cerr << "At line " << __LINE__ << " " << #x << "=" << x << nl
#define dbg2(x, y)                                                             \\
  cerr << "At line " << __LINE__ << " " << #x << "=" << x << " " << #y << "="  \\
       << y << nl
#define dbg3(x, y, z)                                                          \\
  cerr << "At line " << __LINE__ << " " << #x << "=" << x << " " << #y << "="  \\
       << y << " " << #z << "=" << z << nl
#define prv(v)                                                                 \\
  ;                                                                            \\
  rep(i, 0, sz(v)) cerr << v[i] << " ";
#define nl "\\n"
#define sz(s) (int)((s).size())
#define coutsp(k)                                                              \\
  cout << setprecision(                                                        \\
      k) // set precision (total length k icluding decimal and non decimal)
#define coutfsp(k)                                                             \\
  cout << fixed << setprecision(k) // fixed set precision(after decimal fixing)

#define isvowel(a) (a == 'a' || a == 'e' || a == 'i' || a == 'o' || a == 'u')
#define INF (int)2e18

//------------------------ Global VARIABLE ------------------------------------

const int N = 2e5 + 4;

int a[N];
int n;
vi v[N];
//------------------------ Global VARIABLE ------------------------------------
int vis[N];

mii ans;

vector<int> seq;

void dfs(int x) {
  int rem = -1, num;
  if (seq.empty() || seq.back() < a[x])
    seq.push_back(a[x]);
  else {

    num = (lb(seq, a[x]) - seq.begin());
    rem = seq[num];
    seq[num] = a[x];
  }

  ans[x] = sz(seq);

  vis[x] = 1;

  for (auto child : v[x]) {

    if (!vis[child]) {
      dfs(child);
    }
  }

  if (rem == -1)
    seq.pop_back();
  else
    seq[num] = rem;
}

//-------------------------------------------------------------------------------

void dquit() {

  cin >> n;
  rep(i, 1, n + 1) cin >> a[i];

  rep(i, 0, n - 1) {
    int x, y;
    cin >> x >> y;
    v[x].pb(y);
    v[y].pb(x);
  }

  // vi seq;

  dfs(1);

  rep(i, 1, n + 1) cout << ans[i] << nl;
}

//-------------------------------------------------------------------------------

signed main() {

  //--------------------------------
  FAST // MAKE IT FAST   ---
       //--------------------------------

      ///////////////////////////////////////////////////////////////////////////////////////////

      ///////////////////////////////////////////////////////////////////////////////////////////

      int t;
  t = 1;
  int co = 1;
  ///////---------------------------------|||||
  // cin>>t;        ////////>>>>>>>
  //////----------------------------------|||||

  while (t--) {
    // cout<<"Case #"<<co<<": ";

    dquit();
    cout << nl; //  IMPORTANT FOR NEXT LINE
    co++;
  }

  // #ifndef ONLINE_JUDGE
  //  cerr<<(1000*clock())/CLOCKS_PER_SEC<<"ms";
  // #endif

  return 0;
}

Error: WA

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set                                                            \\
  tree<int, null_type, less<int>, rb_tree_tag,                                 \\
       tree_order_statistics_node_update>
#define FAST                                                                   \\
  std::ios_base::sync_with_stdio(false);                                       \\
  cin.tie(0);                                                                  \\
  cout.tie(0);
#define pi acos(-1)
#define mp make_pair
#define pb push_back
#define ALL(v) v.begin(), v.end()
#define SORT(v) sort(ALL(v))
#define REVERSE(v) reverse(ALL(v))
#define F first
#define S second
#define ppb pop_back
#define GCD(m, n) __gcd(m, n)
#define LCM(m, n) (m * n) / GCD(m, n)
#define inputarr(a, n)                                                         \\
  for (int i = 0; i < n; ++i)                                                  \\
  cin >> a[i]
#define initarr(a, n, x)                                                       \\
  for (int i = 0; i < n; ++i)                                                  \\
  a[i] = x
#define rep(i, a, n) for (int i = a; i < n; i++)
#define repe(i, a, n) for (int i = a; i <= n; i++)
#define rev(i, a, b) for (int i = a; i >= b; i--)

#define int long long  ////////////
#define MOD 1000000007 ////////
#define POD 998244353  ////////
// define ll long long
#define ld long double

typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<vvvi> vvvvi;
typedef vector<char> vc;
typedef vector<vc> vvc;
typedef vector<vvc> vvvc;
typedef vector<pii> vpii;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef map<int, int> mii;
typedef unordered_map<int, int> umii;
typedef map<char, int> mci;

#define itv for (auto it = v.begin(); it != v.end(); ++it)
#define present(container, element) (container.find(element) != container.end())
#define cpresent(container, element)                                           \\
  (find(ALL(container), element) != container.end())
// #define invect(data,n,commands) for(int i = 0;i<n;i++){int
// tmp;cin>>tmp;data.pb(tmp);commands} #define inset(data,n,commands) for(int i
// = 0;i<n;i++){int tmp;cin>>tmp;data.insert(tmp);commands} #define trav(a, x)
// for(auto& a : x) #define display(x) trav(a,x) cout<<a<<" ";cout<<endl

#define bs binary_search
#define lb(v, val) lower_bound(ALL(v), val);
#define ub(v, val) upper_bound(ALL(v), val);
#define Max(x, y, z) max(x, max(y, z))
#define Min(x, y, z) min(x, min(y, z))
#define maxc(v) *max_element(ALL(v))
#define minc(v) *min_element(ALL(v))
/*
#define dbg1(a) cout<<" *"<<a<<" ";
#define dbg2(a,b) cout<<" *"<<a<<" **"<<b<<" "     /////
#define dbg cout<<"move"
*/

#define vin(v, n)                                                              \\
  ;                                                                            \\
  vi v(n);                                                                     \\
  rep(i, 0, n) cin >> v[i];
#define dbg cerr << "At line " << __LINE__ << " move " << nl
#define dbg1(x) cerr << "At line " << __LINE__ << " " << #x << "=" << x << nl
#define dbg2(x, y)                                                             \\
  cerr << "At line " << __LINE__ << " " << #x << "=" << x << " " << #y << "="  \\
       << y << nl
#define dbg3(x, y, z)                                                          \\
  cerr << "At line " << __LINE__ << " " << #x << "=" << x << " " << #y << "="  \\
       << y << " " << #z << "=" << z << nl
#define prv(v)                                                                 \\
  ;                                                                            \\
  rep(i, 0, sz(v)) cerr << v[i] << " ";
#define nl "\\n"
#define sz(s) (int)((s).size())
#define coutsp(k)                                                              \\
  cout << setprecision(                                                        \\
      k) // set precision (total length k icluding decimal and non decimal)
#define coutfsp(k)                                                             \\
  cout << fixed << setprecision(k) // fixed set precision(after decimal fixing)

#define isvowel(a) (a == 'a' || a == 'e' || a == 'i' || a == 'o' || a == 'u')
#define INF (int)2e18

//------------------------ Global VARIABLE ------------------------------------

const int N = 2e5 + 4;

int a[N];
int n;
vi v[N];
//------------------------ Global VARIABLE ------------------------------------
int vis[N];

mii ans;

vector<int> seq;

void dfs(int x) {
  int rem = -1;
  auto it = lb(seq, a[x]);
  if (seq.empty() || seq.back() < a[x])
    seq.push_back(a[x]);
  else {
    rem = *it;
    *it = a[x];
  }

  ans[x] = sz(seq);

  vis[x] = 1;

  for (auto child : v[x]) {

    if (!vis[child]) {
      dfs(child);
    }
  }

  if (rem == -1)
    seq.pop_back();
  else
    *it = rem;
}

//-------------------------------------------------------------------------------

void dquit() {

  cin >> n;
  rep(i, 1, n + 1) cin >> a[i];

  rep(i, 0, n - 1) {
    int x, y;
    cin >> x >> y;
    v[x].pb(y);
    v[y].pb(x);
  }

  // vi seq;

  dfs(1);

  rep(i, 1, n + 1) cout << ans[i] << nl;
}

//-------------------------------------------------------------------------------

signed main() {

  //--------------------------------
  FAST // MAKE IT FAST   ---
       //--------------------------------

      ///////////////////////////////////////////////////////////////////////////////////////////

      ///////////////////////////////////////////////////////////////////////////////////////////

      int t;
  t = 1;
  int co = 1;
  ///////---------------------------------|||||
  // cin>>t;        ////////>>>>>>>
  //////----------------------------------|||||

  while (t--) {
    // cout<<"Case #"<<co<<": ";

    dquit();
    cout << nl; //  IMPORTANT FOR NEXT LINE
    co++;
  }

  // #ifndef ONLINE_JUDGE
  //  cerr<<(1000*clock())/CLOCKS_PER_SEC<<"ms";
  // #endif

  return 0;
}