javascript-leetcode面试题解动态规划问题之第64题最小路径和-题解.zip

/** * @param {number[][]} grid * @return {number} */ let minPathSum = function (grid) { let y = grid.length if (!y) { return 0 } let x = grid[0].length let dp = [] for (let i = 0; i < y; i++) { dp[i] = [] } dp[0][0] = grid[0][0] // 第一行的基础状态 记得加上左边格子的值 for (let j = 1; j < x; j++) { dp[0][j] = grid[0][j] + dp[0][j - 1] } // 第一列的基础状态 加上上方格子的最优解即可 for (let i = 1; i < y; i++) { dp[i][0] = grid[i][0] + dp[i - 1][0] } // 开始求左上往右下求解 for (let i = 1; i < grid.length; i++) { for (let j = 1; j < grid[i].length; j++) { let cur = grid[i][j] let fromUp = cur + (dp[i - 1][j] !== undefined ? dp[i - 1][j]: Infinity) let fromLeft = cur + (dp[i][j - 1] !== undefined ? dp[i][j - 1]: Infinity) dp[i][j] = Math.min( fromUp, fromLeft ) } } return dp[y - 1][x - 1] };