Program Segitiga 123

#include <stdio.h>
#include <conio.h>
main()
{
int a,b,c,d,e,f;
printf("masukan tinggi segitiga = ");
scanf("%d",&a);
printf("1\n");
for (c=2;c<=a;c++)
{ b=c;
  printf("%d  ",c);
for (d=1;d<=c;d++)
{if(d==1||d==2)
{
b=b+a-1;
}
else b=b+a+1-d;
printf("%d  ",b);
}
  printf ("\n");
}

getch();
}