Language: C++

#pragma GCC optimize(3,"Ofast","inline")
#include<bits/stdc++.h>
#define ios std::ios::sync_with_stdio(false)
#define rep(i,a,n) for (int i=a;i<=n;i++)
#define per(i,n,a) for (int i=n;i>=a;i--)
#define repp(i,a,b) for(int i=a;i<b;i++)
#define mm(a,n) memset(a, n, sizeof(a))
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define il inline
#define int long long
#define ll long long
#define ull unsigned long long
#define MOD 1000000007
#define pi 3.14159265358979323
#define SZ(x) ((ll)(x).size())
#define debug(x) 		cout<<#x<<": "<<x<<endl;
#define debug2(x,y)     cout<<#x<<": "<<x<<" | "<<#y<<": "<<y<<endl;
#define debug3(x,y,z)   cout<<#x<<": "<<x<<" | "<<#y<<": "<<y<<" | "<<#z<<": "<<z<<endl;
#define debug4(a,b,c,d) cout<<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<endl;
using namespace std;
const ll INF (0x3f3f3f3f3f3f3f3fll);
const int inf (0x3f3f3f3f);
template<typename T>void read(T &res){bool flag=false;char ch;while(!isdigit(ch=getchar()))(ch=='-')&&(flag=true);
for(res=ch-48;isdigit(ch=getchar());res=(res<<1)+(res<<3)+ch - 48);flag&&(res=-res);}
template<typename T>void Out(T x){if(x<0)putchar('-'),x=-x;if(x>9)Out(x/10);putchar(x%10+'0');}
ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
ll lcm(ll a,ll b){return a*b/gcd(a,b);}
ll pow_mod(ll x,ll n,ll mod){ll res=1;while(n){if(n&1)res=res*x%mod;x=x*x%mod;n>>=1;}return res;}
ll fact_pow(ll n,ll p){ll res=0;while(n){n/=p;res+=n;}return res;}
ll mult(ll a,ll b,ll p){a%=p;b%=p;ll r=0,v=a;while(b){if(b&1){r+=v;if(r>p)r-=p;}v<<=1;if(v>p)v-=p;b>>=1;}return r;}
ll quick_pow(ll a,ll b,ll p){ll r=1,v=a%p;while(b){if(b&1)r=mult(r,v,p);v=mult(v,v,p);b>>=1;}return r;}
bool CH(ll a,ll n,ll x,ll t)
{ll r=quick_pow(a,x,n);ll z=r;for(ll i=1;i<=t;i++){r=mult(r,r,n);if(r==1&&z!=1&&z!=n-1)return true;z=r;}return r!=1;}
bool Miller_Rabin(ll n)
{if(n<2)return false;if(n==2)return true;if(!(n&1))return false;ll x=n-1,t=0;while(!(x&1)){x>>=1;t++;}
srand(time(NULL));ll o=8;for(ll i=0;i<o;i++){ll a=rand()%(n-1)+1;if(CH(a,n,x,t))return false;}return true;}
ll exgcd1(ll a,ll b,ll &x,ll &y){if(!b){x=1,y=0;return a;}ll t=exgcd1(b,a%b,y,x);y-=a/b*x;return t;}
ll get_inv(ll a,ll mod){ll x,y;ll d=exgcd1(a,mod,x,y);return d==1?(x%mod+mod)%mod:-1;}
void exgcd(ll a,ll b ,ll &x,ll &y){if(!b){x=1,y=0;return;}exgcd(b,a%b,x,y);ll t=x;x=y,y=t-(a/b)*y;}
ll INV(ll a,ll b){ll x,y;return exgcd(a,b,x,y),(x%b+b)%b;}
ll crt(ll x,ll p,ll mod){return INV(p/mod,mod)*(p/mod)*x;}
ll FAC(ll x,ll a,ll b)
{if(!x)return 1;ll ans=1;for(ll i=1;i<=b;i++)if(i%a)ans*=i,ans%=b;
ans=pow_mod(ans,x/b,b);for(ll i=1;i<=x%b;i++)if(i%a)ans*=i,ans%=b;return ans*FAC(x/a,a,b)%b;}
ll C(ll n,ll m,ll a,ll b)
{ll N=FAC(n,a,b),M=FAC(m,a,b),Z=FAC(n-m,a,b),sum=0,i;for(i=n;i;i=i/a)sum+=i/a;
for(i=m;i;i=i/a)sum-=i/a;for(i=n-m;i;i=i/a)sum-=i/a;return N*pow_mod(a,sum,b)%b*INV(M,b)%b*INV(Z,b)%b;}
ll exlucas(ll n,ll m,ll p)
{ll t=p,ans=0,i;for(i=2;i*i<=p;i++){ll k=1;while(t%i==0){k*=i,t/=i;}
ans+=crt(C(n,m,i,k),p,k),ans%=p;}if(t>1)ans+=crt(C(n,m,t,t),p,t),ans%=p;return ans % p;}
const int N = 3e5 + 10;
const int Max = 1e6 + 10;
struct Dinic
{
    struct Edge
    {
        int to, nex, flow;    //flow?????aì?±?μ±?°μ?±?2Dá?
    } edge[Max << 1];
    int n, m, s, t;
    int head[Max], TOT;
    int dis[Max] , cur[Max];
    void init(int nn , int ss , int tt)
    {
        this->n = nn , this->s = ss , this->t = tt;
        TOT = 1;
        for(int i = 0 ; i <= nn + 1 ; i ++) head[i] = 0;    
    }
    void add_edge(int u , int v , int flow)
    {
        edge[++ TOT].nex = head[u];
        edge[TOT].to = v;
        edge[TOT].flow = flow;
        head[u] = TOT;
        edge[++ TOT].nex = head[v];
        edge[TOT].to = u;
        edge[TOT].flow = 0;
        head[v] = TOT;
    }
    bool bfs() //?D??í?ê?·?á?í¨
    {
        queue<int>que;
        memset(dis, -1, (n + 1) * sizeof(int));
        dis[s] = 0;
        que.push(s);
        while(!que.empty())
        {
            int u = que.front();
            que.pop();
            for(int i = head[u]; i; i = edge[i].nex)
            {
                int v = edge[i].to;
                if(dis[v] == -1 && edge[i].flow > 0)        //?éò??è?ú±?iμ?′?D?μ??áμ?
                {
                    dis[v] = dis[u] + 1;                    //?ó?￥μ?μ??′μ?μ??àà?±ào?
                    que.push(v);
                }
            }
        }
        return dis[t] != -1;                                //è·è?ê?·?á?í¨
    }
    int dfs(int u, int flow_in)
    {
        if(u == t) return flow_in;
        int flow_out = 0;                                    //?????aò?μ?êμ?êá÷3?μ?á÷á?
        for(int i = cur[u]; i; i = edge[i].nex)
        {
            cur[u] = i;                                     //óéóú?ò????1?μ?ê±oò??ê???á?ó????aì?±?μ?èYá??a?°ìáμ?￡?
            // ???′?ú?úó???á÷è?á÷á????°￡??ò??ê1ó?μ?±?￡???ò??-?úá÷á?
            //??óD?ìD???1?μ??é?üá?￡??ùò??×?úá??aD????′μ?±?￡?′ó?′?úá÷μ?±??aê?±éàú
            int v = edge[i].to;
            if(dis[v] == dis[u] + 1 && edge[i].flow > 0)
            {
                int flow_part = dfs(v, min(flow_in, edge[i].flow));
                if(!flow_part)continue;                //?T·¨D?3é??1??·
                flow_in -= flow_part;                        //á÷3?á?ò?2?·?￡?ê￡óà?é·???á÷è??í??éùá?
                flow_out += flow_part;                        //?????aò?μ?×?′óμ?á÷3?
                edge[i].flow -= flow_part;
                edge[i ^ 1].flow += flow_part;                //??éù??1??·é?±?μ?èYá?￡????ó??·′?ò±?μ?èYá?
                if(!flow_in) break;
            }
        }
        return flow_out;
    }
    int dinic()
    {
        int maxflow = 0;
        while(bfs())
        {
            for(int i = 0; i <= n ; i ++) cur[i] = head[i];
            maxflow += dfs(s, INF);
        }
        return maxflow;
    }
}DI;
map<int , int>cntx , cnty;
map<pair<int , int> , int>mp;
signed main()
{
	int n , m , t;
	cin >> n >> m >> t;
	rep(i , 1 , t) 
	{
		int x , y;
		cin >> x >> y;
		mp[make_pair(x , y)] ++ ;
		cntx[x] ++ , cnty[y] ++ ;
	}
	vector<int>vec;
	int ans1 = 0 , ans2 = 0 , ma1 = 0 , ma2 = 0;
	for(auto i : cntx)
	{
		if(ans1 < i.se)
		{
			ans1 = i.se;
			ma1 = i.fi;
			vec.clear();
			vec.pb(ma1);
		}
		else if(ans1 == i.se) vec.pb(i.fi);
	}
	for(auto i : cnty)
	{
		if(ans2 < i.se)
		{
			ans2 = i.se;
			ma2 = i.fi;
			vec1.clear();
			vec1.pb(ma2);
		}
		else if(ans2 == i.se) vec1.pb(i.fi);
	 } 
	int ans = 0; 
	for(auto j : vec)
	for(auto i : vec1)
	{
		int add = 0;
		pair<int , int>now = make_pair(j , i);
		if(mp.count(now)) add = 1;
		ans = max(ans1 + ans2 - add , ans);
	}
	cout << ans << '\n';
	return 0;
}








Compiler output:
a.cc: In function 'int main()':
a.cc:170:25: error: 'vec1' was not declared in this scope; did you mean 'vec'?
  170 |                         vec1.clear();
      |                         ^~~~
      |                         vec
a.cc:173:39: error: 'vec1' was not declared in this scope; did you mean 'vec'?
  173 |                 else if(ans2 == i.se) vec1.pb(i.fi);
      |                                       ^~~~
      |                                       vec
a.cc:177:22: error: 'vec1' was not declared in this scope; did you mean 'vec'?
  177 |         for(auto i : vec1)
      |                      ^~~~
      |                      vec