C++ :

#include<cstdio>
int main()
{
	int n,p=0,t;
	scanf("%d",&n);
	printf("%d\n",n);
	for(int i=1;i<=n;i++)
	{
		p++;
		t=p;
		if(i%2==1)
		{
			for(int j=1;j<=n;j++)
				if(t>0) 
				{
					t--;
					printf("0");
				} 
				else 
				{
					printf("1");
				}
		}
		else 
		{
			for(int j=1;j<=n;j++)
				if(t>0) 
				{
					t--;
					printf("1");
				} 
				else 
				{
					printf("0");
				}
		}
		printf("\n");
	}
}

Pascal :

var n,i,j:longint;
    a:array[1..500] of longint;

begin
 read(n);

 writeln(n);
 for i:=1 to n do begin
  for j:=1 to n do if i<>j then
   if a[j]=0 then a[j]:=1 else a[j]:=0;
  for j:=1 to n do write(a[j]);
  writeln;
 end;

end.