Implementation of Quadratic Search in c++

QuadraticSearch.cpp

/* Implementation of Quadratic Search in c++
 * Research Paper : https://research.ijcaonline.org/volume65/number14/pxc3886165.pdf
 * Author : Parveen Kumar
 * Code Author: Anish Shobith P S
 */
#include<bits/stdc++.h>

class QuadraticSearch
{
    private:
        std::vector<int> a;
        int n, i, ele, loc = -1;
    public: 
        void inputData();
        int search();
        void display();
};

void QuadraticSearch::inputData()
{
    std::cout<<"Enter the size of the array = ";
    std::cin>>n;
    
    int input;
    
    std::cout<<"Enter the elements into the array = \n";
    for (i = 0; i < n; i++)
    {
        std::cin>>input;
        a.push_back(input);
    }
    
    std::cout<<"Enter the element to be searched = ";
    std::cin>>ele;
}

int QuadraticSearch::search()
{
    int P1 = 0,P2 = 0,MID = 0, FIRST = 0, LAST = n - 1;
    
    while(FIRST <= LAST)
    {
        MID = (FIRST + LAST) / 2;
        P1 = FIRST + (LAST- FIRST) / 4;
        P2 = FIRST + (LAST- FIRST) * 3 / 4;
        
        if (ele == a[MID] || ele == a[P1] || ele == a[P2])
        {
            loc = ele == a[MID] ? MID : ele == a[P1] ? P1 : P2;
            return loc;
        }
        else if(ele < a[MID] && ele < a[P1])
            LAST = P1 - 1;
        else if(ele < a[MID] && ele > a[P1])
        {
            FIRST = P1 + 1;
            LAST = MID - 1;
        }
        else if(ele > a[MID] && ele > a[P2])
            FIRST = P2 + 1;
        else if(ele > a[MID] && ele < a[P2])
        {
            FIRST = MID + 1;
            LAST = P2 - 1;
        }
    }
    return loc;
}

void QuadraticSearch::display()
{
    if (loc == -1)
        std::cout<<"Element "<<ele<<" not found in the array"<<std::endl;
    else
        std::cout<<"Element is found at the location = "<<loc + 1<<std::endl;
}

int main()
{
    QuadraticSearch Qs;
    Qs.inputData();
    Qs.search();
    Qs.display();
    getchar();
    return 0;
};