func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m;   int a[2005][2005];   bitset<2000> b[2000];   bitset<2000> c[2000];   int u[500005], v[500005];   template <class T>   void dbg(T x) {     for (int i = 0; i < n; i++) {       for (int j = 0; j < n; j++) {         cout << (int)x[i][j];       }       cout <<   n ;     }     cout <<   n ;   }   int main() {     cin >> n >> m;     for (int i = 0; i < m; i++) {       cin >> u[i] >> v[i];       a[u[i]][v[i]] = 1;       b[u[i] - 1][v[i] - 1] = 1;     }     for (int i = 0; i < n; i++) {       c[i][i] = 1;     }     for (int i = 0; i < n; i++) {       for (int j = i; j < n; j++) {         if (b[j][i] == 1) {           swap(b[i], b[j]);           swap(c[i], c[j]);           break;         }       }       for (int j = i + 1; j < n; j++) {         if (b[j][i]) {           b[j] ^= b[i];           c[j] ^= c[i];         }       }     }     for (int i = n - 1; i > 0; i--) {       for (int j = i - 1; j >= 0; j--) {         if (b[j][i]) {           b[j] ^= b[i];           c[j] ^= c[i];         }       }     }     for (int i = 0; i < m; i++) {       int x = u[i] - 1, y = v[i] - 1;       if (c[y][x]) {         cout <<  NO n ;       } else {         cout <<  YES n ;       }     }   }   