输入一个数字，打印出如下，用while 循环

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int a;
    cin>>a;
    int l=1;
    while(l!=a+1)
    {
        for(int i=1;i<=l*2-1-l+1;i++)
        cout<<l<<" ";
        cout<<"\n";
        l++;
    }
}