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.
Example:
Given nums = [2, 7, 11, 15], target = 9, Because nums[0] + nums[1] = 2 + 7 = 9, return [0, 1].
class Solution { public: map<int, int> mp; vector<int> twoSum(vector<int>& nums, int target) { int size = nums.size(); for(int i = 0; i < size; i++){ int tmp = mp[nums[i]]; if(tmp != 0) return {--tmp, i}; tmp = target - nums[i]; mp[tmp] = i + 1; } return {-1, -1}; } };
原文：http://www.cnblogs.com/Pretty9/p/7816746.html