Java for LeetCode 063 Unique Paths II

標籤：

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.

解題思路：

本題如果使用上題中的解法一，將會非常複雜，因此我們修改解法二即可，JAVA實現如下：

public int uniquePathsWithObstacles(int[][] obstacleGrid) {        int[] v = new int[obstacleGrid[0].length];for (int i = 0; i < v.length; i++)if (obstacleGrid[0][i] == 0)v[i] = 1;elsebreak;for (int i = 1; i < obstacleGrid.length; i++) {if (obstacleGrid[i][0] == 1)v[0] = 0;for (int j = 1; j < v.length; j++)if (obstacleGrid[i][j] == 1)v[j] = 0;elsev[j] += v[j - 1];}return v[v.length - 1];    }

 

Java for LeetCode 063 Unique Paths II