标签：span class 集合 val tco two sum not style push
题目：
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 sameelement twice.
Example:
Given nums = [2, 7, 11, 15], target = 9, Because nums[0] + nums[1] = 2 + 7 = 9, return [0, 1].
题解：
Solution 1 （my submmision）
class Solution { public: vector<int> twoSum(vector<int>& nums, int target) { vector<int> res; unordered_map<int, int> map; for(int i = 0; i < nums.size(); ++i){ int val = target - nums[i]; if(map.find(val) != map.end()){ res.push_back(map[val]); map[nums[i]] = i; res.push_back(map[nums[i]]); break; } map[nums[i]] = i; } return res; } };
Solution 2
class Solution { public: vector<int> twoSum(vector<int>& nums, int target) { vector<int> res; unordered_map<int, int> map; for(int i = 0; i < nums.size(); ++i){ if(map.find(nums[i]) == map.end()){ map[target - nums[i]] = i; } else { res.push_back(map[nums[i]]); res.push_back(i); break; } } return res; } };
相当于建立数组中每个元素的相对应的加数的集合，这个加数对应了原数组中元素的坐标。
标签：span class 集合 val tco two sum not style push
原文地址：http://www.cnblogs.com/Atanisi/p/7467951.html
