[백준 1484] 다이어트 (Two Pointer) (C/C++)

#include <stdio.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <math.h>
using namespace std;
 
int main(void)
{
//    freopen("B1484_input.txt", "r", stdin);
    
    long long G;
    vector<long long> result;
        
    cin >> G;
    
    long long left = 1;
    long long right = 1;
    
    while(left <= right && right <= G+1)
    {
        if(right*right - left*left > G)
        {
            left++;
        }
        else if(right*right - left*left < G)
        {
            right++;
        }
        else if(right*right - left*left == G)
        {
            result.push_back(right);
            
            right++;
        }
    }
    
    if(result.size() == 0)
    {
        cout << -1;
    }
    else
    {
        for(int i = 0; i < result.size(); i++)
        {
            cout << result[i] << endl;
        }
    }
 
    return 0;
}