Queue implementation using array

StaticQueue.c

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

# define CAPACITY 5
int queue[CAPACITY], top = -1, base = -1;

//prototyping
void enQueue(int);
int isEmpty(void);
int isFull(void);
void deQueue(void);
void traverse(void);
void peek(void);
//------------------------------------------------------------------------------
int main(){

  while(1){
    printf("\nSelect your choice\n");
    printf(" 1. enQueue \n 2. deQueue \n 3. Traverse \n 4. Peek \n 5. Exit\n");
    int option;
    printf("Enter your choice : ");
    scanf("%d",&option);

    switch(option){
      case 1 : printf("\nEnter the number you want to enQueue : ");
               int num;
               scanf("%d",&num);
               enQueue(num);
               break;
      case 2 : deQueue();
               break;
      case 3 : traverse();
               break;
      case 4 : peek();
               break;
      case 5 : exit(0);
               break;
      default : printf("\nInvalid Input\n");
    }
  }
}
//------------------------------------------------------------------------------
void enQueue (int num){
  if (isEmpty()){
    base = 0;
    top = 0;
    queue[top] = num;
  }
  else{
    if(isFull()){
      printf("\nNo space to enQueue new element\n");
    }
    else{
      top++;
      queue[top] = num;
    }

  }
}
//------------------------------------------------------------------------------
int isEmpty(){
  if (base == -1 && top == -1){
    return 1;
  }
  else {
    return 0;  
  }
}
//------------------------------------------------------------------------------
int isFull(){
  if (top == CAPACITY-1){
    return 1;
  }
  else{
    return 0;
  }
}
//------------------------------------------------------------------------------
void deQueue(){
  if (top == -1){
    printf("\nNo element to dequeue\n");    
  }
  else if (top == 0){
    printf("\ndeQueued element : %d\n", queue[top]);
    base = -1 ;     
    top = -1 ;    
  }
  else{
    printf("\ndeQueued element : %d\n", queue[base]);
    for (int i=1 ; i<=top ; i++){
      queue[i-1] = queue[i];
    }
    top--;
    
  }
}
//------------------------------------------------------------------------------
void traverse(){
  if(isEmpty()){
    printf("\nQueue is empty.\n");
  }
  else{
    printf("\nElements in queue : ");
    for (int i =0 ; i <= top ; i++){
      printf("%d ", queue[i]);
    }
    printf("\n\n");
  }
}
//------------------------------------------------------------------------------
void peek(){
  if (isEmpty()){
    printf("\nQueue is empty.\n");
  }
  else{
    printf("\nPeek of queue : %d\n",queue[top]);
  }
}