*Leetcode 377. Combination Sum IV | dp

https://leetcode.com/problems/combination-sum-iv/description/

比较直白的递推了

class Solution {
public:
    int combinationSum4(vector<int>& nums, int target) {
        vector<int> dp(target+1, 0);

        sort(nums.begin(), nums.end());
        dp[0] = 1;
        for (int i = 1; i <= target; i++) {
            dp[i] = 0;
            for (int j = 0 ; j < nums.size(); j++) {
                    if (nums[j] > i) break;
                    int v = i - nums[j];
                    dp[i] += dp[v];
                }
        }

        return dp[target];
    }
};