[99클럽 코테 스터디 41일차 TIL] Unique Paths II

💡문제

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

 

💡키워드

• 동적계획법

 

💡접근/해결 방법

✅ 풀이

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