Source Code : Program that implements queue as an array.

_{Program that implements queue as an array. */}

_#include

_#include

_{#define MAX 10}

_{void addq ( int *, int, int *, int * ) ;}

_{int delq ( int *, int *, int * ) ;}

_{void main( )}

_{

  _{int arr[MAX] ;}

  _{int front = -1, rear = -1, i ;}

  _{clrscr( ) ;}

  _{addq ( arr, 23, &front, &rear ) ;}

  _{addq ( arr, 9, &front, &rear ) ;}

  _{addq ( arr, 11, &front, &rear ) ;}

  _{addq ( arr, -10, &front, &rear ) ;}

  _{addq ( arr, 25, &front, &rear ) ;}

  _{addq ( arr, 16, &front, &rear ) ;}

  _{addq ( arr, 17, &front, &rear ) ;}

  _{addq ( arr, 22, &front, &rear ) ;}

  _{addq ( arr, 19, &front, &rear ) ;}

  _{addq ( arr, 30, &front, &rear ) ;}

  _{addq ( arr, 32, &front, &rear ) ;}

  _{i = delq ( arr, &front, &rear ) ;}

  _{printf ( "\nItem deleted: %d", i ) ;}

  _{i = delq ( arr, &front, &rear ) ;}

  _{printf ( "\nItem deleted: %d", i ) ;}

  _{i = delq ( arr, &front, &rear ) ;}

  _{printf ( "\nItem deleted: %d", i ) ;}

  _{getch( ) ;}

_}

_{/* adds an element to the queue */}

_{void addq ( int *arr, int item, int *pfront, int *prear  )}

_{

  _{if ( *prear == MAX - 1 )}

  _{

  _{printf ( "\nQueue is full." ) ;}

  _{return ;}

  _}

  _{( *prear )++ ;}

  _{arr[*prear] = item ;}

  _{if ( *pfront == -1 )}

  _{*pfront = 0 ;}

_}

_{/* removes an element from the queue */}

_{int delq ( int *arr, int *pfront, int *prear )}

_{

  _{int data ;}

  _{if ( *pfront == -1 )}

  _{

  _{printf ( "\nQueue is Empty." ) ;}

  _{return NULL ;}

  _}

  _{data = arr[*pfront] ;}

  _{arr[*pfront] = 0 ;}

  _{if ( *pfront == *prear )}

  _{*pfront = *prear = -1 ;}

  _else

  _{( *pfront )++ ;}

  _{return  data ;}

_}