[LintCode] 最小路径和

 1 class Solution {
 2 public:
 3     /**
 4      * @param grid: a list of lists of integers.
 5      * @return: An integer, minimizes the sum of all numbers along its path
 6      */
 7     int minPathSum(vector<vector<int> > &grid) {
 8         // write your code here
 9         int m = grid.size();
10         int n = grid[0].size();
11         vector<int> cur(m, grid[0][0]);
12         for (int i = 1; i < m; i++)
13             cur[i] = cur[i - 1] + grid[i][0];
14         for (int j = 1; j < n; j++) {
15             cur[0] += grid[0][j];
16             for (int i = 1; i < m; i++)
17                 cur[i] = min(cur[i - 1], cur[i]) + grid[i][j];
18         }
19         return cur[m - 1];
20     }
21 };