34.A

/*

1

0 1

1 0 1

0 1 0 1

1 0 1 0 1

*/

#include<stdio.h>

#include<conio.h>

main() {

int i, j;

int count = 1;

for (i = 1; i <= 4; i++) {

printf("\n");

for (j = 1; j <= i; j++) {

printf("%d", count % 2);

count++;

}

if (i % 2 == 0)

count = 1;

else

count = 0;

}

getch();

}