LeetCode问题

1、Two Sum
   """Given an array of integers, return indices of the two numbers such that they add up to a specific target.You may assume that each input would have exactly one solution, and you may not use the same element twice.

Example:

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

Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].

思路：
用dictionary 存期望得到的数{期望数:期望数的index}（期望数= 目标数-当前数）
循环list 判断期望值是否在 dict 如果存在 则 返回对应的key  否则存期望数，接着找

"""

def twoSum(nums, target):

    """

    :type nums: List[int]

    :type target: int

    :rtype: List[int]

    """

    dict_num = {}

    for key, value in enumerate(nums):

        depand = target - value

        if dict_num.__contains__(depand):

            return dict_num.get(depand), key

        dict_num[value] = key

if __name__ == '__main__':

    print(twoSum([, , , ], ))