Notes

#include "../headerfiles/stack.h"

/*** AVAILABLE FUNCTIONS ***/
int isEmpty(Stack*);
void push(Stack*, int);
int pop(Stack*);
int peek(Stack*);

typedef struct {
int cur;
Stack s[2];
} Queue;

//Using two stacks implement all essential functions of a queue: enqueue, dequeue and isEmptyQueue
void enqueue(Queue * q, int x) {
//TODO: Store the incoming value in the first stack (1 line)
push(&q->s[q->cur],x);
//TODO ENDS
}

int dequeue(Queue * q) {
//TODO: Pop and return a value from second stack but if second stack is empty, unload all the values from first stack to the second and then return the value from the second stack (4-7 lines)
if(isEmpty(&q->s[1-q->cur]))
while(!isEmpty(&q->s[q->cur]))
push(&q->s[1-q->cur],pop(&q->s[q->cur]));
return pop(&q->s[1-q->cur]);
//TODO ENDS
}

int isEmptyQueue(Queue * q) {
//TODO: Check is values are available on at least one of the stacks (1 line)
return (isEmpty(&q->s[q->cur]) && isEmpty(&q->s[1-q->cur]));
//TODO ENDS
}

int main() {
int integers[] = {3, 1, 4, 1, 5, 9, 2, 6, 5, 4, -1};
//ASSIGNMENTS
Queue q = {0};
for(int i = 0; integers[i]!=-1; ++i) enqueue(&q, integers[i]);
while(!isEmptyQueue(&q)) printf("%d ", dequeue(&q));
printf("n");
}