Multi Stacks in Single Array

Implement multi stack in a single array.

Source Code

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

int stack[50],top[50],min[50],max[50];
int ns,size;

int main(){
  int ele,ch,skn;
  init();
  printf("Enter the number of Stacks\n");
  scanf("%d",&ns);
  size = 50/ns;
  createstack();
  printf("::Stack Operations::\n1.Push\n2.Pop\n3.Display\n4.Exit\n");
  do{
    printf("Enter your choice : \n");
    scanf("%d",&ch);
    switch(ch){
      case 1:
        printf("\nEnter the stack no : \n");
        scanf("%d",&skn);
        printf("\nEnter the element : \n");
        scanf("%d",&ele);
        push(ele,skn);
        break;
      case 2:
        printf("Enter the stack no to pop : \n");
        scanf("%d",&skn);
        pop(skn);
        break;
      case 3:
        printf("\nEnter the stack no to display : \n");
        scanf("%d",&skn);
        display(skn);
        break;
      case 4:
        printf("\nProgram Terminating");
        break;
      default:
        printf("\nInvalid Option\n");
    }
  }while(ch!=4);
  return 0;
}

void init(void){
  int i;
  for(i=0;i<50;++i){
    stack[i]=min[i]=max[i] = 0;
    top[i]=-1;
  }
}

void createstack(){
  int i ;
  min[0]= -1;
  max[0] = size -1;
  top[0]=-1;
  for(i=1;i<ns;++i){
    min[i]= min[i-1] + size;
    top[i] = min [i];
  }
  for(i=1;i<ns;++i){
    max[i]= min[i+1];
  }
}

void push(int ele,int k){
  if(top[k-1]==max[k-1]){
    printf("Stack no %d is full i.e overflow\n",k);
    return;
  }
  ++top[k-1];
  stack[top[k-1]] = ele;
}

void pop(int k){
  if(top[k-1]==min[k-1]){
    printf("Stack no %d is empty i.e underflow\n",k);
    return;
  }
  printf("%d from stack %d is deleted:\n",stack[top[k-1]],k);
  --top[k-1];
}

void display(int k){
  int j;
  if(top[k-1]==min[k-1]){
    printf("\nStack no %d is empty\n",k);
    return;
  }
  printf("\nStack %d -> ",k);
  for(j=min[k-1]+1;j<=top[k-1];++j){
    printf("%d ",stack[j] );
  }
  printf("\n");
}

Enter the number of Stacks
2
::Stack Operations::
1. Push
2. Pop
3. Display
4. Exit
Enter your choice :
1
Enter the stack no :
1
Enter the element :
2
Enter your choice :
1
Enter the stack no :
1
Enter the element :
4
Enter your choice :
1
Enter the stack no :
1
Enter the element :
6
Enter your choice :
3
Enter the stack no to display :
1
Stack 1 -> 2 4 6
Enter your choice :
3
Enter the stack no to display :
2
Stack no 2 is empty
Enter your choice :
1
Enter the stack no :
2
Enter the element :
1
Enter your choice :
1
Enter the stack no :
2
Enter the element :
3
Enter your choice :
3
Enter the stack no to display :
2
Stack 2 -> 1 3
Enter your choice :
4
Program Terminating