Little Monkey Programming C++ | Greatest Common Divisor of Intervals

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[Title description]

The little monkey recently learned the basic knowledge of the greatest common divisor in mathematics class. In order to strengthen the little monkey's understanding of the greatest common divisor, Teacher H assigned the little monkey a homework question:

The little monkey needs   to choose any two integers  x and y between L ∼ R ( L ≤ x < y ≤ R ), and  the greatest common divisor of x and y is required to be the largest .

Please help the little monkey complete this task.

【enter】

A line contains two  integers L and R.

【Output】

A line containing an integer representing the answer.

【Input sample】

23 29

【Output sample】

4

[Detailed code explanation]

#include <bits/stdc++.h>
using namespace std;

int main()
{
    int L, R;
    cin >> L >> R;
    for (int i=R/2; i>=1; i--) {
        if (R/i - (L-1)/i >= 2) {
            cout << i;
            return 0;
        }
    }
    return 0;
}

【operation result】

23 29
4