pattern numbers in rectangular

#include<iostream>
using namespace std;
int main()
{
    int n;
    cin>>n;
    int i=1;
    while(i<=n){                 //for reverse number use j=n-j+1
        int j=1;
        while(j<=n){
            cout<<j;
            j=j+1;
        }
        cout<<endl;
        i=i+1;
    }
}