377. 组合总和 Ⅳ

class Solution:
    def combinationSum4(self, nums: List[int], target: int) -> int:
        dp = [0] * (target + 1)
        dp[0] = 1
        for i in range(1, target + 1):
            for num in nums:
                if i >= num:
                    dp[i] += dp[i - num]
        return dp[-1]

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 num : nums) {
                if (i >= num) {
                    dp[i] += dp[i - num];
                }
            }
        }
        return dp[target];
    }
}

class Solution {
public:
    int combinationSum4(vector<int>& nums, int target) {
        vector<int> dp(target + 1);
        dp[0] = 1;
        for (int i = 1; i <= target; ++i) {
            for (int num : nums) {
                if (i >= num && dp[i - num] < INT_MAX - dp[i]) {
                    dp[i] += dp[i - num];
                }
            }
        }
        return dp[target];
    }
};

func combinationSum4(nums []int, target int) int {
	dp := make([]int, target+1)
	dp[0] = 1
	for i := 1; i <= target; i++ {
		for _, num := range nums {
			if i >= num {
				dp[i] += dp[i-num]
			}
		}
	}
	return dp[target]
}

/**
 * @param {number[]} nums
 * @param {number} target
 * @return {number}
 */
var combinationSum4 = function (nums, target) {
    const dp = new Array(target + 1).fill(0);
    dp[0] = 1;
    for (let i = 1; i <= target; ++i) {
        for (let v of nums) {
            if (i >= v) {
                dp[i] += dp[i - v];
            }
        }
    }
    return dp[target];
};