It is very simple:
Code:
#include <stdio.h>
#include <stdlib.h>
int main()
{
int n, i, j;
printf("How many rows you want to show?: ");
scanf("%d", &n);
for (i=0; i<n; i++) {
int c = 1;
for(j=i; j>=0; j--) {
printf(" %d", c);
c = c * j/(i-j+1);
}
printf("\n");
}
}