Source Code
#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<iomanip>
#include<string>
#include<cmath>
#include<vector>
#include<set>
#include<queue>
#include<stack>
#include<fstream>
#include<map>
#include<bitset>
#include<unordered_map>
#include<cstring>
#include<cctype>
using namespace std;
#define  ll long long
#define  ull unsigned long long
#define  ul unsigned long
#define all(v) v.begin(),v.end()
#define allr(v) v.rbegin(),v.rend()
#define sz(n) (int)n.size()
#define pb(s) push_back(s);
#define format(n) fixed<<setprecision(n)
#define finl "\n"
#define Mohammed_Atef_Hassan fast();
#define md 1000000007
#define INF LLONG_MAX
#define PI acos(-1)
#define clr(dp,n) memset(dp,n,sizeof dp)
#define ex(n) return cout<<n<<finl,0;
int dx[] = { 0, 1, 0, -1, 1, 1, -1, -1 };
int dy[] = { 1, 0, -1, 0, 1, -1, 1, -1 };
ll fix_mod(ll x, ll y)
{
    return (y + x % y) % y;
}
void fast()
{
    std::ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

#ifdef ONLINE_JUDGE
    //freopen("crosses.in", "r", stdin);

    //freopen("crosses.out", "w", stdout);
#endif
#ifndef ONLINE_JUDGE
    freopen("input.in", "r", stdin);
    //freopen("output.out", "w", stdout);
#endif
}
int main()
{
    Mohammed_Atef_Hassan
    int t;
    cin>>t;
    while(t--)
    {
        ll n,a;
        cin>>n>>a;
        ll ans=0;double res=LLONG_MIN;
        for(ll i=max(1LL,n-300);i<=n;i++)
        {
            double cur=log(a)+log(i)-2*log(__gcd(a,i));
            if(cur>res)
            {
                res=cur;
                ans=i;
            }
        }
        cout<<ans<<finl;
    }
}
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LCM and GCD MuhammedAtefHassan
GNU G++17
1711 ms
516 KB
Wrong Answer