Problem
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.
Note:
- Your returned answers (both index1 and index2) are not zero-based.
- You may assume that each input would have exactly one solution and you may not use the same element twice.
Example
Input: numbers = [2,7,11,15], target = 9
Output: [1,2]
Explanation: The sum of 2 and 7 is 9. Therefore index1 = 1, index2 = 2.
Code
static int var = [](){
std::ios::sync_with_stdio(false);
cin.tie(NULL);
return 0;
}();
class Solution {
public:
vector<int> twoSum(vector<int>& numbers, int target) {
vector<int> res;
int i = 0,j=numbers.size()-1;
int tmp = 0;
while((tmp=numbers[i]+numbers[j])!=target){
if(tmp>target)
j--;
if(tmp<target)
i++;
}
res.push_back(i+1);
res.push_back(j+1);
return res;
}
};
167. Two Sum II - Input array is sorted.png
