Minimum Path Sum

题目

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.

方法

从左上方到右下方，仅仅能向下和向右移动。

按行进行处理。

    public int minPathSum(int[][] grid) {if (grid == null) {return 0;}int lenI = grid.length;if (lenI == 0) {return 0;}int lenJ = grid[0].length;if (lenJ == 0) {return 0;}for (int i = 0; i < lenI; i++) {for (int j = 0; j < lenJ; j++) {if (!(i == 0 && j ==0)) {if (i == 0) {grid[i][j] = grid[i][j - 1] + grid[i][j];} else if (j == 0) {grid[i][j] = grid[i - 1][j] + grid[i][j];} else {grid[i][j] = Math.min(grid[i][j - 1] + grid[i][j], grid[i - 1][j] + grid[i][j]);}}}}return grid[lenI - 1][lenJ - 1];}