Leetcode 377. Combination Sum IV

2016-07-27 分类：算法阅读(4977) 评论(0) 赞(0)

题目链接：Combination Sum IV

Given an integer array with all positive numbers and no duplicates, find the number of possible combinations that add up to a positive integer target.

　　赤裸裸的完全背包，属于动态规划的范畴，大家有兴趣可以在网上搜索下其他资料。个人觉得动态规划还是比较难理解的，更难给别人讲清楚，所以这里我直接附上我的代码供大家参考。

public class Solution {
    public int combinationSum4(int[] nums, int target) {
        int[] dp = new int[target+1];
        dp[0] = 1;
        for (int i = 1; i <= target; i++) {
            for (int j = 0; j < nums.length; j++) {
                if (i >= nums[j]) {
                    dp[i] += dp[i-nums[j]];
                }
            }
        }
        return dp[target];
    }
}