leetcode系列 - Two Sum(Easy) 给一个包含integer的数组，如果数组中两个数的和为给的目标数，

题目简介

给一个包含integer的数组，如果数组中两个数的和为给的目标数，则返回这两个数的索引，你可以假设每次输入有一个解决方案，并且你不会两次使用同一个值。
(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.)

Swift (Swift version 3.1)

func twoSum(_ nums: [Int], _ target: Int) -> [Int] {
    var result = [Int]()
    for i in 0 ..< nums.count {
        for j in (i + 1) ..< nums.count {
            if nums[i] + nums[j] == target {
                result = [i, j]
            }
        }
    }
    return result
}

Python (Version 3.5)

def twoSum(self, nums, target):
        dict = {}
        for i in range(len(nums)):
            x = nums[i]
            if target - x in dict:
                return (dict[target - x], i)
            dict[x] = i