[LeetCode]Two Sum

很常见和基础的题目，输入不一定是sorted的，用hashset解决。时间空间复杂度均为O(N)，代码如下：

	class Solution {
	public:
	vector<int> twoSum(vector<int>& nums, int target) {
	unordered_map<int, int> map;
	int len = nums.size();
	for(int i = 0; i < len; ++i)
	{
	int toFind = target - nums[i];
	if(map.find(toFind) != map.end())
	return {map[toFind], i};
	map[nums[i]] = i;
	}
	return {};
	}
	};

view raw Two Sum.cpp hosted with ❤ by GitHub