Today's Challenge

https://leetcode.com/problems/unique-paths-ii/

Unique Paths II - LeetCode

전형적인 DP 문제긴 한데..
오늘도 시간이 없어서 open 된 solution보고 따라 쳐봄.

class Solution:
    def uniquePathsWithObstacles(self, obstacleGrid: List[List[int]]) -> int:
        m = len(obstacleGrid)
        n = len(obstacleGrid[0])
        
        if obstacleGrid[0][0] == 1:
            return 0
        
        obstacleGrid[0][0] = 1
        
        for i in range(1, m):
            obstacleGrid[i][0] = int(obstacleGrid[i][0] == 0 and obstacleGrid[i-1][0] == 1)
            
        for j in range(1, n):
            obstacleGrid[0][j] = int(obstacleGrid[0][j] == 0 and obstacleGrid[0][j-1] == 1)
            
        for i in range(1, m):
            for j in range(1, n):
                if obstacleGrid[i][j] == 0:
                    obstacleGrid[i][j] = obstacleGrid[i-1][j] + obstacleGrid[i][j-1]
                else:
                    obstacleGrid[i][j] = 0
        
        return obstacleGrid[m-1][n-1]