LeetCode 之 Two Sum

原题：

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

这个题比较简单，用两个for判断就可以，不过为了节省时间，当遇到numbers[i]>target时，可以continue，直到检测出两个数的和等于target

代码（ 20
ms）：

class Solution {
public:
vector<int> twoSum(vector<int> &numbers, int target) {
// IMPORTANT: Please reset any member data you declared, as
// the same Solution instance will be reused for each test case.

vector<int>result;

for (int i =0;i<numbers.size();i++){
//当遇到大于target时，continue
if(numbers[i]>target) continue;
for (int j = i+1 ;j<numbers.size();j++){
if(numbers[j]>target) continue;
if( (numbers[i] + numbers[j])==target ){
result.push_back(i+1);
result.push_back(j+1);
return result;
}
}
}
}
};