#include <stdio.h>
#include <stdlib.h>

#define MAXWORD 100

int    get_call_from_user(void);
void   play(int how_many);
void   prn_final_report(int win, int lose, int how_many);
void   prn_instructions(void);
void   report_a_win(int coin);
void   report_a_loss(int coin);
int    toss(void);
------------------------------------------------------------------------
#include "heads.h"

int main(void)
{
   char   ans;
   int    no_of_plays;

   printf("\n"
      "THE GAME OF HEADS OR TAILS\n"
      "\n"
      "Do you want instructions?  ");
   scanf(" %c", &ans);
   putchar('\n');
   if (ans == 'y' || ans == 'Y')
      prn_instructions();
   printf("How many times do you want to play?  ");
   scanf("%d", & no_of_plays);
   putchar('\n');
   play( no_of_plays);
   return 0;
}
-------------------------------------------------------------------
#include "heads.h"

int get_call_from_user(void)
{
   int   guess;                /* 0 = heads, 1 = tails */

   do {
      printf("Call it:  ");
      if (scanf("%d", &guess) != 1) {
         printf("\nSORRY: Severe input error - bye!\n\n");
         exit(1);
      }
      if (guess != 0 && guess != 1) {
         printf("\n%s\n\n",
            "ERROR: Type 0 for heads, 1 for tails.");
      }
   } while (guess != 0 && guess != 1);
   return guess;
}
-----------------------------------------------------------------
#include "heads.h"

void prn_instructions(void)
{
   printf("%s\n",
      "This is the game of calling heads or tails.\n"
      "I will flip a coin; you call it.  If you\n"
      "call it correctly, you win; otherwise,\n"
      "I win.\n"
      "\n"
      "As I toss the (simulated) coin, I will\n"
      "tell you to \"call it.\"  To call heads,\n"
      "type 0; to call tails, type 1.\n"
      "\n");
}

void prn_final_report(int win, int lose, int how_many)
{
   printf("\n%s\n%s%3d\n%s%3d\n%s%3d\n\n",
      "FINAL REPORT:",
      "   Number of games that you won:  ", win,
      "   Number of games that you lost: ", lose,
      "   Total number of games:         ", how_many);
}
------------------------------------------------------------------
#include "heads.h"
  void report_a_win(int coin)
{
	printf("You win, it was a");
	if (coin)
	{
		printf("tail\n");
	}
	else
	{
		printf("head\n");
	}
	return;
}

void report_a_lose(int coin)
{
	printf("You lose, it was a");
	if (coin)
	{
		printf("tail\n");
	}
	else
	{
		printf("head\n");
	}
	return;
} 

int toss(void)
{
   return (rand() % 2);     /* 0 = heads, 1 = tails */
}