LeetCode:Unique Paths II

标签：algorithm   leetcode   

题目描述：

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.

代码：

int uniquePathsWithObstacles(vector<vector<int> > &obstacleGrid)
{
    int i,j;
    int m = obstacleGrid.size();
    int n = obstacleGrid[0].size();

    int ** pathCount = (int**)(malloc(sizeof(int*)*m));
    for(i = 0;i < m;i++)
        pathCount[i] = (int*)malloc(sizeof(int)*n);

    for(i = 0;i < n;i++)
        if(obstacleGrid[0][i] == 0)
            pathCount[0][i] = 1;
        else
            break;
    for(;i < n;i++)
        pathCount[0][i] = 0;

    for(i = 0;i < m;i++)
        if(obstacleGrid[i][0] == 0)
            pathCount[i][0] = 1;
        else
            break;
    for(;i < m;i++)
        pathCount[i][0] = 0;

    for(i = 1;i < m;i++)
        for(j = 1;j < n;j++)
    {
        if(obstacleGrid[i][j] == 1)
            pathCount[i][j] = 0;
        else
            pathCount[i][j] = pathCount[i-1][j] + pathCount[i][j-1];
    }
    return pathCount[m-1][n-1];
}

LeetCode:Unique Paths II

标签：algorithm   leetcode   

原文地址：http://blog.csdn.net/yao_wust/article/details/42234591