func_code_string: #include <bits/stdc++.h>   using namespace std;   void FREOPEN() {}   inline double Time() { return (clock() * 1.0) / CLOCKS_PER_SEC; }   const int N = (int)2000, inf = (int)2e9, MOD = (int)1e9 + 7, alph = 26;   char CH[N];   const long long INF = (long long)1e18;   const int dx[] = {1, -1, 0, 0, -1, 1, -1, 1};   const int dy[] = {0, 0, 1, -1, -1, 1, 1, -1};   const int dp[] = {8, 9, 1, 13, 3, 12, 7, 5, 0, 2, 4, 11, 6, 10, 15, 14};   int a[N][N];   int main() {     FREOPEN();     int n;     cin >> n;     int num = 0;     for (int bi = 0; bi < n; bi += 4) {       for (int bj = 0; bj < n; bj += 4) {         for (int i = bi; i < bi + 4; i++) {           for (int j = bj; j < bj + 4; j++) {             int p = (i - bi) * 4 + (j - bj);             a[i][j] = (dp[p] ^ num);           }         }         num += 16;       }     }     for (int i = 0; i < n; i++) {       for (int j = 0; j < n; j++) printf( %d  , a[i][j]);       printf(  n );     }     return 0;   }   