Implementation of stack using 2 queues

#include <stdio.h>
#define m 100

int q1[m], q2[m];
int rear1 = -1, rear2 = -1, front1 = -1, front2 = -1;

void enque(int x, int *rear, int *front, int q[m]){
    if (*rear == -1 && *front == -1){
        (*rear)++;
        (*front)++;
        q[*rear] = x;
    }
    else if (*rear == m-1){
        printf("\nOverflowing!!!");
    }
    else{
        (*rear)++;
        q[*rear] = x;
    }
    //printf("\n%d is inserted!!", q[*rear]);
}

int deque(int *rear, int *front, int q[m]){
    int d = -1;
    if (*rear == -1 && *front == -1){
        printf("\nUnderflowing!!");
    }
    else if (*rear == *front){
        d = q[*front];
        *rear = -1;
        *front = -1;
    }
    else{
        d = q[*front];
        (*front)++;
    }
    return d;
}

int top(int *rear, int *front, int q[m]){
    return q[*front];
}

int isEmpty(int q[m], int *rear, int *front){
    if (*rear == -1 && *front == -1){
        return 1;
    }
    return 0;
}

void push(int x){
    enque(x, &rear1, &front1, q1);
     while (!isEmpty(q2, &rear2, &front2)){
        int y = top(&rear2, &front2, q2);
        enque(y, &rear1, &front1, q1);
        deque(&rear2, &front2, q2);
    }
     while (!isEmpty(q1, &rear1, &front1)){
        int y = top(&rear1, &front1, q1);
        enque(y, &rear2, &front2, q2);
        deque(&rear1, &front1, q1);
    }
}

void pop(){
    printf("\t%d ", deque(&rear2, &front2, q2));
}

int main(){
    push(1);
    push(2);
    push(3);
    push(4);
    pop();
    pop();
    pop();
    pop();
    return 0;
}