Two Sum

问题

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.

例子

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

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

解决方案

class Solution:
    def twoSum(self, num, target):
        tmp = {}
        for i in range(len(num)):
            if target - num[i] in tmp:
                return(tmp[target - num[i]], i)
            else:
                tmp[num[i]] = i;