class Solution:

    def twoSum(self,nums,target):
        #求出列表的长度
        n = len(nums)
        #创建一个空的字典存放减数
        d = {}
        for x in range(n):
            #利用a和字典中的数字匹配
            a = target - nums[x]

            if nums[x] in d:
                return d[nums[x]],x

            else:
                d[a] = x

nums = [2,7,11,15]
target = 9

a = Solution()
print(a.twoSum(nums,target))