leetcode刷题之Two Sum

Python3

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.

Example: 
Given nums = [2, 7, 11, 15], target = 9, 
Because nums[0] + nums[1] = 2 + 7 = 9, 
return [0, 1].

代码：Runtime: 40 ms

class Solution:
    def twoSum(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: List[int]
        """
        keys={}
        for i in range(len(nums)):
            if target-nums[i] in keys:
                return [keys[target-nums[i]],i]
            if nums[i] not in keys:
                keys[nums[i]]=i