LeetCode: Minimum Path Sum

题目

https://oj.leetcode.com/problems/minimum-path-sum/

分析

动态规划题，

某一点的MinimumPathSum = min(左侧点的MinimumPathSum, 上侧点的MinimumPathSum) + 该点的数值

不过第一行和第一列的MinimumPathSum有些特殊，需要单独处理一下。

代码

class Solution
{
public:
int minPathSum(vector<vector<int>> &grid)
{
int m = grid.size();
int n = grid[0].size();
vector<vector<int>> res(grid);

//First row and first col 's Minimum Path Sum
for (int i = 1; i < m; i++)
res[i][0] += res[i-1][0];
for (int i = 1; i < n; i++)
res[0][i] += res[0][i-1];

//Other points's Minimum Path Sum
for (int i = 1; i < m; i++)
for (int j = 1; j < n; j++)
res[i][j] += min(res[i-1][j], res[i][j-1]);

return res[m-1][n-1];
}
};