题目:原题链接(中等)
标签:动态规划、数组
| 解法 | 时间复杂度 | 空间复杂度 | 执行用时 | 
| Ans 1 (Python) | O ( N 2 ) | O ( N ) | 60ms (25.32%) | 
| Ans 2 (Python) | |||
| Ans 3 (Python) | 
解法一:
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 num <= i:
                    dp[i] += dp[i - num]
        return dp[target]









