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.
Example 1:
[[1,3,1],
[1,5,1],
[4,2,1]]
Given the above grid map, return 7
. Because the path 1→3→1→1→1 minimizes the sum.
题意:找到数组中的最短路径
思路:动态规划
java代码:
class Solution {
public int minPathSum(int[][] grid) {
for (int i = 1; i < grid.length; i++) {
grid[i][0] += grid[i - 1][0];
}
for (int j = 1; j < grid[0].length; j++) {
grid[0][j] += grid[0][j - 1];
}
for (int i = 1; i < grid.length; i++) {
for (int j = 1; j < grid[0].length; j++) {
grid[i][j] = Math.min(grid[i][j - 1], grid[i - 1][j]) + grid[i][j];
}
}
return grid[grid.length - 1][grid[0].length - 1];
}
}
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