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.
思路
同样使用动态规划 类似于上几题
public class Solution {
public int minPathSum(int[][] grid) {
int m = grid.length;
int n = grid[0].length;
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]; //初始
}else if(i == 0 && j != 0){
grid[i][j] = grid[i][j] + grid[i][j-1]; //第一行的初始化 应为只能向右走
}else if(i != 0 && j == 0){
grid[i][j] = grid[i][j] + grid[i-1][j]; //第一列的初始化 应为只能向下走
}else{
grid[i][j] = Math.min(grid[i-1][j] , grid[i][j-1]) + grid[i][j];
}
}
}
return grid[m - 1][n - 1];
}
}