# 算法题丨Two Sum

### 描述

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.

### 示例

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

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


### 代码示例(C#)

public int[] TwoSum(int[] nums, int target)
{
var map = new Hashtable(); ;
for (int i = 0; i < nums.Length; i++)
{
int complement = target - nums[i];
//匹配成功，返回结果
if (map.ContainsKey(complement))
{
return new int[] { (int)map[complement], i };
}