Hình vuông

THA

#include<iostream>
#include<vector>
using namespace std;
typedef long long ll;
int main(){
	freopen("VUONG.INP","r",stdin);
	freopen("VUONG.OUT","w",stdout);
	int n,m,x,y,ans=0;
	cin>>n>>m;
	vector<vector<int>>mat(n+1,vector<int>(m+1,-1)),dp(n+1,vector<int>(m+1,0));
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			cin>>mat[i][j];
			dp[i][j]=1;
			if(mat[i][j]==mat[i-1][j]&&mat[i][j]==mat[i][j-1]&&mat[i][j]==mat[i-1][j-1]){
				dp[i][j]=min(dp[i-1][j-1],min(dp[i-1][j],dp[i][j-1]))+1;
			} 
			if(ans<dp[i][j]){
				int v=dp[i][j];
				ans=v;
				x=i-v+1;
				y=j-v+1;
			}
		}
	}
	cout<<ans<<endl;
	cout<<x<<" "<<y<<endl;
}