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

// draws numbers from a jar without replacement
#define MAXNUM 75 // highest number in bingo

void InitializeJar (int injar[]);
void PrintJar (int []);
int IsJarEmpty (int current);
int PickNum (int [], int);
void CallOut (int num, int calln);

int main ()
{
   int jar[MAXNUM];
   int newnum;
   int callnum=0;

   srand(1237);
   InitializeJar(jar);
   PrintJar (jar);
   // until the jar is empty or someone wins
   while (!IsJarEmpty(callnum))
   {
      // pick a number and update the jar
      newnum = PickNum(jar, callnum);
      // call out the number
      CallOut(newnum,callnum);
      callnum++;
   }
   return 0;
}

void InitializeJar (int injar[])
{
   int i;
   int index;
   int temp;
   float random;

   for(i=0;i<MAXNUM;i++)
   {
      injar[i]=i+1;
   }

   for(i=0;i<MAXNUM;i++)
   {
      random = rand();
      // pick the index of the number to be swapped
      index = MAXNUM * random/RAND_MAX;
      // swap injar[index] with injar[i]
      temp = injar[index];
      injar[index] = injar[i];
      injar[i] = temp;
   }
   return;
}

void PrintJar (int injar[])
{
   int i;
   for(i=0;i<MAXNUM;i++)
   {
      printf("%d: %d\n",i,injar[i]);
   }
   return;
}

int IsJarEmpty (int current)
{
   // Note: in this version, remain is replaced by current, which is
   // an index to the current item, not a number of remaining items
   return current == MAXNUM;
}

int PickNum (int injar[], int current)
{
   return injar[current];
}

void CallOut (int num, int calln)
{
   printf("Call number %d: %d\n", calln+1, num);
   return;
}