C Program For Peek Operation In Stack

 

C PROGRAM FOR PEEK OPERATION IN STACK

CODE

#include<stdio.h>

#include<stdlib.h>

struct stack

{

int top;

int size;

int *arr;

};

int stackEmpty(struct stack *ptr)

{

if(ptr->top==-1)

return 1;

else

return 0;

}

int stackFull(struct stack *ptr)

{

if(ptr->top==ptr->size-1)

return 1;

else

return 0;

}

void push(struct stack *ptr, int data)

{

if(stackFull(ptr))

printf("Cannot push %d to the stack\n",data);

else

{

ptr->top++;

ptr->arr[ptr->top]=data;

printf("Pushed %d to the stack\n",data);

}

}

void pop(struct stack *ptr)

{

if(stackEmpty(ptr))

printf("Stack underflow\n");

else

{

int temp=ptr->arr[ptr->top];

ptr->top--;

printf("Popped %d from the stack\n",temp);

}

}

void peek(struct stack *ptr, int i)

{

if(stackEmpty(ptr))

printf("Stack underflow\n");

else

{

int arrindex= ptr->top-i+1;

printf("Element at position %d is %d\n", i, ptr->arr[arrindex]);

}

}

int main()

{

int j;

struct stack *sp=(struct stack *)malloc(sizeof(struct stack));

sp->size=5;

sp->top=-1;

sp->arr=(int *)malloc(sizeof(int)*sp->size);

push(sp,2);

push(sp,3);

push(sp,4);

push(sp,6);

push(sp,7);

push(sp,3);

for(j=1;j<=sp->top+1;j++)

{

peek(sp,j);

}

return 0;

}

OUTPUT