377 Combination Sum IV

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

solution

• 完全背包

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 >= 0:
                    dp[i] += dp[i - num]
        return dp[target]

时间复杂度：O() 空间复杂度：O()