Two Sum

Two Sum

题目

Given an array of integers, find two numbers such that they add up to a specific target number.

The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2. Please note that your returned answers (both index1 and index2) are not zero-based.

You may assume that each input would have exactly one solution.

Input: numbers={2, 7, 11, 15}, target=9

Output: index1=1, index2=2

译文

给定一个整数数组，找出相加等于特定目标数的两个数。函数twoSum返回两个数在数组中的位置，index1必须比index2小，两个数都不是从零开始的。你可以假设每组输入都只有一个确定的答案。

分析

难度medium

我的代码

class Solution {
public:
vector<int> twoSum(vector<int> &numbers, int target) {
int i, sum;
vector<int> results;
map<int, int> hmap;
for(i=0; i<numbers.size(); i++){
if(!hmap.count(numbers[i])){
hmap.insert(pair<int, int>(numbers[i], i));
}
if(hmap.count(target-numbers[i])){
int n=hmap[target-numbers[i]];
if(n<i){
results.push_back(n+1);
results.push_back(i+1);
cout<<n+1<<", "<<i+1<<endl;
return results;
}
}
}
return results;
}
};