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.
Solution
public class Solution {
public int uniquePathsWithObstacles(int[][] obstacleGrid) {
int m = obstacleGrid.length;
int n = obstacleGrid[0].length;
int[][] result = new int[m][n];
for(int i = 0; i < m; i ++) {
if (obstacleGrid[i][0] == 0) {
result[i][0] = 1;
} else {
break;
}
}
for(int j = 0; j < n; j ++) {
if (obstacleGrid[0][j] == 0) {
result[0][j] = 1;
} else {
break;
}
}
for(int i = 1; i < m; i ++) {
for(int j = 1; j < n; j ++) {
if (obstacleGrid[i][j] == 0) {
result[i][j] = result[i - 1][j] + result[i][j - 1];
}
}
}
return result[m-1][n-1];
}
}