quack.h
#include <stdio.h> #include <stdlib.h> #include <assert.h> typedef struct node *Quack; Quack createQuack(void); void push(int data, Quack qs); void qush(int data, Quack qs); int pop(Quack qs); void makeEmptyQuack(Quack qs); int isEmptyQuack(Quack qs); void showQuack(Quack qs);
quack.c
#include "quack.h"
#define HEIGHT 1000
struct node{
int array[HEIGHT];
int top;
};
Quack createQuack(void){
Quack qs;
qs = malloc(sizeof(struct node));
if (qs == NULL){
fprintf(stderr, "Out of memory~
");
exit(EXIT_FAILURE);
}
qs->top = -1;
return qs;
}
void push(int data, Quack qs){
if (qs == NULL){
fprintf(stderr, "push: quack not initialised
");
}
else {
if (qs->top >= HEIGHT - 1){
fprintf(stderr, "push: quack overflow
");
}
else {
++qs->top;
qs->array[qs->top] = data;
}
}
return;
}
//used as queue, push element from bottom
void qush(int data, Quack qs){
if (qs == NULL){
fprintf(stderr, "qush: quack not initialised
");
}
else {
if (qs->top >= HEIGHT - 1) {
fprintf(stderr, "qush: quack overflow
");
}
else {
for (int i = qs->top + 1; i > 0; i--) {
qs->array[i] = qs->array[i-1];
}
qs->array[0] = data;
qs->top++;
}
}
return;
}
int pop(Quack qs){
int retval = 0;
if (qs == NULL){
fprintf(stderr, "pop: quack not initialised
");
}
else {
if (isEmptyQuack(qs)){
fprintf(stderr, "pop: quack underflow
");
}
else {
retval = qs->array[qs->top];
--qs->top;
}
}
return retval;
}
void makeEmptyQuack(Quack qs){
if (qs == NULL){
fprintf(stderr, "makeEmptyQuack: quack not initialised
");
}
else {
while (!isEmptyQuack(qs)) {
pop(qs);
}
}
return;
}
int isEmptyQuack(Quack qs) {
// 0 means not empty
int empty = 0;
if (qs == NULL){
fprintf(stderr, "isEmptyQuack: quack not initialised
");
}
else {
empty = qs->top < 0;
}
return empty;
}
void showQuack(Quack qs) {
if (qs == NULL){
fprintf(stderr, "showQuack: quack not initialised
");
}
else {
printf("Quack: ");
if (qs->top < 0) {
printf("<< >>
");
}
else {
int i;
printf("<<");
for (i = qs->top; i > 0; i--){
printf("%d, ", qs->array[i]);
}
printf("%d>>
", qs->array[0]);
}
}
return;
}
separateQuack.c
// separateQuack.c: have both a stack and a queue in the same program
#include <stdio.h>
#include "quack.h"
int main(void) {
Quack s = NULL;
Quack q = NULL;
s = createQuack();
q = createQuack();
push(1, s);
push(2, s);
printf("pop from s produces %d
", pop(s));
printf("pop from s produces %d
", pop(s));
qush(1, q);
qush(2, q);
printf("pop from q produces %d
", pop(q));
printf("pop from q produces %d
", pop(q));
//
printf("
----------------------------------
");
push(1, s);
push(2, s);
printf("pop from s produces %d
", pop(s));
printf("pop from s produces %d
", pop(s));
qush(1, q);
qush(2, q);
printf("pop from q produces %d
", pop(q));
printf("pop from q produces %d
", pop(q));
//
printf("
----------------------------------
");
printf("
stack example
");
for (int i = 0; i < 4; i++) {
printf("push: %d -- ", i+1);
push(i+1, s);
showQuack(s);
}
for (int i = 0; i < 4; i++) {
printf("pop: %d --- ", pop(s));
showQuack(s);
}
printf("
queue example
");
for (int i = 0; i < 4; i++) {
printf("qush: %d -- ", i+1);
qush(i+1, s);
showQuack(s);
}
for (int i = 0; i < 4; i++) {
printf("pop: %d --- ", pop(s));
showQuack(s);
}
return EXIT_SUCCESS;
}
Run in terminal
gcc quack.c separateQuack.c && ./a.out
output:
pop from s produces 2 pop from s produces 1 pop from q produces 1 pop from q produces 2 ---------------------------------- pop from s produces 2 pop from s produces 1 pop from q produces 1 pop from q produces 2 ---------------------------------- stack example push: 1 -- Quack: <<1>> push: 2 -- Quack: <<2, 1>> push: 3 -- Quack: <<3, 2, 1>> push: 4 -- Quack: <<4, 3, 2, 1>> pop: 4 --- Quack: <<3, 2, 1>> pop: 3 --- Quack: <<2, 1>> pop: 2 --- Quack: <<1>> pop: 1 --- Quack: << >> queue example qush: 1 -- Quack: <<1>> qush: 2 -- Quack: <<1, 2>> qush: 3 -- Quack: <<1, 2, 3>> qush: 4 -- Quack: <<1, 2, 3, 4>> pop: 1 --- Quack: <<2, 3, 4>> pop: 2 --- Quack: <<3, 4>> pop: 3 --- Quack: <<4>> pop: 4 --- Quack: << >>