func_code_string: #include <bits/stdc++.h>   using namespace std;   const long double pi = 2 * acos(0.0);   long long infinity = std::numeric_limits<long long>::max();   long long binary_search(long long dp[], long long n, long long p) {     long long l, r, mid;     l = 0;     r = n - 1;     sort(dp, dp + n);     while (l <= r && l >= 0 && l <= n - 1 && r >= 0 && r <= n - 1) {       mid = (l + r) / 2;       if (dp[mid] >= p) {         r = mid - 1;       } else {         l = mid + 1;       }     }     return l;   }   struct order {     long long l, r;   };   bool compare(order o1, order o2) {     if (o1.l == o2.l)       return (o1.r < o2.r);     else       return (o1.l < o2.l);   }   bool check(order o1, order o2) { return (o1.r < o2.l); }   int main() {     long long t;     cin >> t;     while (t--) {       long long r, c, k, num_R = 0, i, j;       cin >> r >> c >> k;       char A[r][c];       for (i = 0; i < r; ++i)         for (j = 0; j < c; ++j) {           cin >> A[i][j];           num_R += (A[i][j] ==  R );         }       long long x = ceil((double)num_R / (double)k), a, b, c1 = 0, x_count = 0,                 y_count = 0;       char req = 48;       b = x * k - num_R;       a = k - b;       long long a1 = a, b1 = b, l = 0, f = 0;       for (i = 0; i < r; ++i) {         if (i % 2 == 0)           j = 0;         else           j = c - 1;         while ((i % 2 == 0 && j < c) || (i % 2 == 1 && j >= 0)) {           if (A[i][j] !=  R )             A[i][j] = req;           else {             A[i][j] = req;             ++c1;             if (c1 == x * a) {               c1 = 0;               x = x - 1;               a = b;               if (l == 1 || a == 0) {                 f = 1;                 break;               }               if (a != 0) ++req;               ++l;             } else if (c1 % x == 0) {               ++req;             }           }           if (i % 2 == 0)             ++j;           else             --j;           if (req == 58)             req = 65;           else if (req == 91)             req = 97;         }         if (f == 1) {           break;         }       }       for (i = 0; i < r; ++i) {         for (j = 0; j < c; ++j) {           if (A[i][j] !=  . )             cout << A[i][j];           else             cout << req;         }         cout <<   n ;       }     }     return 0;   }   