practice_2.cpp

#include <iostream>
using namespace std;

void dispBin(int i){
    bool next = true;
    for(int j=0;j<=i;j++,next=!next){
        cout<<next;
    }
}

int main() {
    int n,i,j,ni;
    bool flip=true;
    cin>>n;
    for(i=0,ni=0 ; ni<n ; ni++,i-=(1-(2*flip)),flip=(i<((n/2))&&flip)){
        dispBin((i==n/2)?i-1:i);
        for(j=0 ; j<(n-((i+1)*2)) ; j++)cout<<' ';
        dispBin(i);
        //cout<<' '<<i<<' '<<flip;
        cout<<endl;
    }
    return 0;
}