View Compilation Error

0_0_39304612_4208.cpp: In function 'void Solve()':
0_0_39304612_4208.cpp:23:36: error: 'd' was not declared in this scope
   23 |       for (int u = 0; u <= n; u++) d[u][i] = dp[u][i - 1];
      |                                    ^