[Leetcode] Minimum Path Sum

Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.

Note: You can only move either down or right at any point in time.

水

class Solution {
public:
int minPathSum(vector<vector<int> > &grid) {
int m = grid.size();
int n = grid[0].size();
for (int i = 0; i < m; ++i) {
for (int j = 0; j < n; ++j) {
if (i == 0 && j != 0) {
grid[i][j] += grid[i][j-1];
}
if (i != 0 && j == 0) {
grid[i][j] += grid[i-1][j];
}
if (i != 0 && j != 0) {
grid[i][j] += min(grid[i-1][j], grid[i][j-1]);
}
}
}
return grid[m-1][n-1];
}
};