很离谱，我用PII stk[N * N],代替vector在输入30*30的大数据时，我的n = 23,m = 18。调试了半天没搞明白，最后用vector一遍过！！！！

#include <iostream>
#include <queue>
#include <vector>

using namespace std;
typedef pair<int,int> PII;
const int N = 40;
int g[N][N];
// PII stk[N * N];
vector<PII> stk;
// int tt = -1;
int n,m;

int main(){
    cin >> n >> m;
    int p = n,l = m;
    for(int i = 1;i <= n;i++)
        for(int j = 1;j <= m;j++)
            cin >> g[i][j];
    // cout << n << ' ' << m << endl;
    for(int k = 1;k <= n;k++){
        for(int j = 1;j <= m;j++){
                int times = 1,val = g[k][j],x = j;
                stk.push_back({k,j});
                // stk[++tt] = ;
            for(int i = j + 1;i <= m;i++){
                if(val == g[k][i] && val != 0 && i - x == 1){
                    times++;
                    stk.push_back({k,i});
                    x = i;
                } 
            }
            if(times < 3)
                while(times--) stk.pop_back();
        }
    }

    for(int k = 1;k <= m;k++){
        for(int j = 1;j <= n;j++){
                int times = 1,val = g[j][k],x = j;
                stk.push_back({j,k});
            for(int i = j + 1;i <= n;i++){
                if(val == g[i][k] && val != 0 && i - x == 1){
                    times++;
                    stk.push_back({i,k});
                    x = i;
                } 
            }
            if(times < 3)
                while(times--) stk.pop_back();
        }
    }
    for(int i = 0;i < stk.size();i++){
        auto t = stk[i];
        g[t.first][t.second] = 0;
    }
    for(int i = 1;i <= n;i++){
        for(int j = 1;j <= m;j++){
            cout << g[i][j] << ' ';
        }
        cout << endl;
    }

    return 0;
}