粉刷房子(leetcode)

问题

解答 （动态规划+深度优先搜索）

/**
 * @param {number[][]} costs
 * @return {number}
 */
var minCost = function(costs) {
    var dp = [];
    var n = costs.length;
    var max = 9999999;
    for(let i = 0; i <= n; i++) {
        dp[i] = [];
        for(let j = 0; j <= 2; j++) {
            dp[i][j] = max;
        }
    }
    const dfs = (pos, d) => {
        if(pos == n) { return 0; }
        let min = max;
        for(let i = 0; i <= 2; i++) {
            if(d == i) { continue; }
            if(dp[pos][i] >= max) {
                dp[pos][i] =Math.min(dfs(pos+1,i) + costs[pos][i],dp[pos][i]);
            }
            min = Math.min(dp[pos][i],min);
        }
        return min;
    }
    return dfs(0,-1);
};