1017C - The Phone Number - CodeForces Solution

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

const int N = 2e5 + 5;
const int MOD = 1e9 + 7;
const int inf  = LLONG_MAX;


int32_t main(){
std::ios_base ::sync_with_stdio(false);
std::cin.tie(NULL);
std::cout.tie(NULL);
std::cout << std::fixed << std::setprecision(25);
    int n ; cin >>  n ; 
    int jk = (int) sqrt ( n );
    int target = n /jk * jk;
    int p = n  ; 
    int prnt = target +1 ;
    if ( target == n ){
        target -= jk ; 
        prnt = target + 1 ;
    }
    for ( int  i = 0; i < n ; i++)
    {
        cout << prnt << " " ; 
        prnt ++ ; 
        if ( prnt > p ){
            p = target ; 
            target -= jk ; 
            prnt = target + 1 ; 
        }
    }
    
return 0;
}