Codeforces Round #813 (Div. 2) 1712B. Woeful Permutation Solution

 Problem Link:  https://codeforces.com/contest/1712/problem/B\

Solution in C++:

///La ilaha illellahu muhammadur rasulullah

///******Bismillahir-Rahmanir-Rahim******///

///Abul Hasnat  Tonmoy

///Department of CSE,23rd batch

///Islamic University,Bangladesh

///**********ALLAH IS ALMIGHTY************///

#include <bits/stdc++.h>

using namespace std;

#define ll long long int

int main()

{

    ios_base::sync_with_stdio(0);

    cin.tie(0);

    ll  n,t,i,j,cnt=0,ans;

    cin>>t;

    while(t--)

    {

        cin>>n;

        if(n==1)

            cout<<"1"<<endl;

        else

        {

            if(n%2==0)

            {

                for(i=1; i<=n; i++)

                {

                    if(i%2==0)cout<<i-1<<" ";

                    else cout<<i+1<<" ";

                }

                cout<<endl;

            }

            else

            {

                for(i=1; i<=n; i++)

                {

                    if(i==1)cout<<"1 ";

                    else if(i%2==0)cout<<i+1<<" ";

                    else cout<<i-1<<" ";

                }

                cout<<endl;

            }

        }

    }

}