题目大意：给出一个三维矩阵，求子矩阵和最大值。

解题思路：现将各个平面上的矩阵记录下矩阵和，然后可以枚举二维上的矩阵，映射成三维去做。

#include 
   
     #include 
    
      using namespace std; int main() { int T; scanf(%d, &T); while (T--) { int A, B, C; long long tmp, s[25][25][25] = {0}; scanf(%d%d%d, &A, &B, &C); for (int i = 1; i <= A; i++) for (int j = 1; j <= B; j++) for (int k = 1; k <= C; k++) { scanf(%lld, &tmp); s[i][j][k] = s[i][j][k-1] + s[i][j-1][k] - s[i][j-1][k-1] + tmp; } long long ans = -0x3f3f3f3f3f3f3f; for (int m = 1; m <= B; m++) for (int n = m; n <= B; n++) for (int p = 1; p <= C; p++) for (int q = p; q <= C; q++) { long long MAX = 0; for (int x = 1; x <= A; x++) { long long sum = s[x][n][q] - s[x][m-1][q] - s[x][n][p-1] + s[x][m-1][p-1]; MAX = max(MAX + sum, sum); ans = max(ans, MAX); } } printf(%lld , ans); if (T) printf( ); } return 0; } 
    
   

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