LeetCode 62 Unique Paths II

Follow up for "Unique Paths":

Now consider if some obstacles are added to the grids. How many unique paths would there be?

An obstacle and empty space is marked as 1 and 0 respectively in the grid.

For example,

There is one obstacle in the middle of a 3x3 grid as illustrated below.

[  [0,0,0],  [0,1,0],  [0,0,0]]

The total number of unique paths is 2.

Note: m and n will be at most 100.

思路：与LeetCode 61 Unique Paths 的思路一样点http://blog.csdn.net/mlweixiao/article/details/37569159

public class Solution {public int uniquePathsWithObstacles(int[][] obstacleGrid) {int m = obstacleGrid.length;int n = obstacleGrid[0].length;int[][] grid = new int[m][n];int i, j;boolean flag = false;for (i = 0; i < m; i++) {if (obstacleGrid[i][0] == 1)flag = true;if (!flag)grid[i][0] = 1;}flag = false;for (i = 0; i < n; i++) {if (obstacleGrid[0][i] == 1)flag = true;if (!flag)grid[0][i] = 1;}for (i = 1; i < m; i++) {for (j = 1; j < n; j++) {if (obstacleGrid[i][j] == 0)grid[i][j] = grid[i - 1][j] + grid[i][j - 1];}}return grid[m - 1][n - 1];}}