diff --git a/problems/0063.不同路径II.md b/problems/0063.不同路径II.md index 6b81225c..f78995e9 100644 --- a/problems/0063.不同路径II.md +++ b/problems/0063.不同路径II.md @@ -382,8 +382,37 @@ var uniquePathsWithObstacles = function(obstacleGrid) { return dp[m - 1][n - 1] }; + +// 版本二:内存优化,直接以原数组为dp数组 +var uniquePathsWithObstacles = function(obstacleGrid) { + const m = obstacleGrid.length; + const n = obstacleGrid[0].length; + for (let i = 0; i < m; i++) { + for (let j = 0; j < n; j++) { + if (obstacleGrid[i][j] === 0) { + // 不是障碍物 + if (i === 0) { + // 取左边的值 + obstacleGrid[i][j] = obstacleGrid[i][j - 1] ?? 1; + } else if (j === 0) { + // 取上边的值 + obstacleGrid[i][j] = obstacleGrid[i - 1]?.[j] ?? 1; + } else { + // 取左边和上边的和 + obstacleGrid[i][j] = obstacleGrid[i - 1][j] + obstacleGrid[i][j - 1]; + } + } else { + // 如果是障碍物,则路径为0 + obstacleGrid[i][j] = 0; + } + } + } + return obstacleGrid[m - 1][n - 1]; +}; ``` + + ### TypeScript ```typescript