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