leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
Log | Files | Refs | README | LICENSE

1504.cpp (745B)

      1 class Solution {
      2   public:
      3     int numSubmat(vector<vector<int>> &mat) const {
      4         const int n = size(mat), m = size(mat[0]);
      5 
      6         for (int j = 0; j < m; j++) {
      7             for (int i = 0, acc = 0; i < n; i++) {
      8                 if (mat[i][j])
      9                     mat[i][j] = acc += 1;
     10                 else
     11                     acc = 0;
     12             }
     13         }
     14 
     15         int res = 0;
     16         for (int i = 0; i < n; i++) {
     17             for (int j = 0; j < m; j++) {
     18                 int mini = mat[i][j];
     19                 for (int k = j; k >= 0; k--) {
     20                     mini = min(mini, mat[i][k]);
     21                     if (!mini) break;
     22                     res += mini;
     23                 }
     24             }
     25         }
     26         return res;
     27     }
     28 };