C Program to Calculate all possible Combinations of an n Digit Number

Generally a question is asked that if you have given n bits then print out all the possible binary numbers of n bit and so I will try to explain how to get that done. Please don't Copy Paste. Understand The logic because it is useful in other problems as well

for eg
if n=1 then you can have
0
1
if n=2 then you can have
00
10
01
11

Similarly if n=3 then you can have 8 possible combination.

In general for a n bit number you can have 2 to the power n possible numbers. 

Code:

#include <stdio.h>
#define ARRAY_SIZE 200
/* FUNCTIONS DECLARATIONS */
void find_all_possible_binary(int ,int );
void push(int );
void pop();

/******************************************************************************
* SIMPLE LIFO STACK .YOU CAN ADJUST ARRAY_SIZE ACCORDING TO YOUR SYSTEM MEMORY
replace pf with printf
*/
int stack[ARRAY_SIZE];
int top;

void push(int x){
 stack[++top]=x;
}

void pop(){
 stack[top--];
}
/******************************************************************************/

void find_all_possible_binary(int x,int temp)
{
 int i;
 if(temp!=-1){
  push(temp);
 } 
 if(x==0){
  for( i=0;i<=top;++i)
   pf("%d",stack[i]);
  pf("\n");
  pop();
 }
 else{   
  find_all_possible_binary(x-1,0);
  find_all_possible_binary(x-1,1);
  pop();        
 }
}
int main(){
 int no_of_bits;
 top=-1;
 pf("Enter number of bits: ");
 scanf("%d",&no_of_bits);
 find_all_possible_binary(no_of_bits,-1);
}