LeetCode64 最小路径和

最新推荐文章于 2020-05-19 10:31:11 发布

fruit513

最新推荐文章于 2020-05-19 10:31:11 发布

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本文链接：https://blog.youkuaiyun.com/fruit513/article/details/85917945

本文介绍了一种在矩阵中寻找从左上角到右下角的最小路径和的算法。该算法通过动态规划逐步更新每个位置的最小路径和，最终得到整个矩阵的最小路径和。举例说明了算法的应用过程。

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:

Input:
[
[1,3,1],
[1,5,1],
[4,2,1]
]
Output: 7
Explanation: Because the path 1→3→1→1→1 minimizes the sum.

class Solution {
    public int minPathSum(int[][] grid) {
	int m = grid.length;// row
	int n = grid[0].length; // column
	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] + grid[i][j - 1];
			} else if (i != 0 && j == 0) {
				grid[i][j] = grid[i][j] + grid[i - 1][j];
			} else if (i == 0 && j == 0) {
				grid[i][j] = grid[i][j];
			} else {
				grid[i][j] = Math.min(grid[i][j - 1], grid[i - 1][j])
						+ grid[i][j];
			}
		}
	}

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