leetcode167

1、Two Sum II - Input array is sorted
Given an array of integers that is already sorted in ascending order, 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
既然数组都是升序排好了，而且只有一对满足，就从小到大寻找好了，两个循环的终止条件是个重点嗯～

class Solution {
public:
    vector<int> twoSum(vector<int>& numbers, int target) {
        vector<int> result;
        for(int i=0;numbers[i]<=target;i++){
            int gap=target-numbers[i];
            for(int j=i+1;numbers[j]<=gap;j++){
                if(numbers[j]==gap){
                    result.push_back(i+1);
                    result.push_back(j+1);
                }
            }
        }
        return result;
    }
};