Question

Time limit: 5000ms
Memory limit: 256mb

Description:
Given a series of stack operations, please complete the stack ADT to output for respective operations.

-------------------------Copy the following code, complete it and submit-------------------------
#include <stdio.h>
#include <stdlib.h>

typedef enum {push = 1, pop, end} Operation;

typedef struct Node * PtrToNode;

struct Node {
    int element;
    PtrToNode next;
    PtrToNode prev;
};

typedef struct ListRecord * List;

struct ListRecord {
    PtrToNode head;
    PtrToNode tail;
};

List Create() {
    List L;
    L = (List)malloc(sizeof(struct ListRecord));
    L->head = (PtrToNode)malloc(sizeof(struct Node));
    L->head->prev = NULL;
    L->tail = (PtrToNode)malloc(sizeof(struct Node));
    L->head->next = L->tail;
    L->tail->prev = L->head;
    L->tail->next = NULL;
    return L;
}

void Insertion(int x, List L) {
    // write your code here
}

int Deletion(List L) {
    // write your code here
}

Operation Getop() {
    char str[7];
    scanf("%s", str);
    if (strcmp(str, "Push") == 0) {
        return 1;
    }
    else if (strcmp(str, "Pop") == 0) {
        return 2;
    }
    else {
        return 3;
    }
}

void printList(List L) {
    PtrToNode ptr;
    ptr = L->head->next;
    while(ptr != L->tail) {
        printf("%d ", ptr->element);
        ptr = ptr->next;
    }
}

int main(void) {
    int X;
    List L;
    int flag = 0;

    L = Create();
    while (!flag) {
        switch(Getop()) {
            case push:
                scanf("%d", &X);
                Insertion(X, L);
                break;
            case pop:
                X = Deletion(L);
                if (X == 1e5) {
                    printf("Stack is empty\n");
                }
                break;
            case end:
                printList(L);
                flag = 1;
                break;
        }
    }
    return 0;
}

-------------------------------------------End of Code-------------------------------------------

Input:
M lines of stack operations, each chosen from one of the followings: Push x(an integer) and Pop, except the last of which, which is End.

Output
A line per Pop (if stack is empty) operation, denoting the stack is empty, following by a line of remaining elements in the stack from bottom to top upon End

Sample Input 1:
Pop
Push 1
Push 2
Pop
End

Sample Output 1:
Stack is Empty
1

Sample Input 2:
Pop
Push 1
End

Sample Output 2:
Stack is empty
1

Answer 1

Note:

Used the code provided in the Question and updated the code that you need.

The code in the Bold format is the Updated code.

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

typedef enum {push = 1, pop, end} Operation;

typedef struct Node * PtrToNode;

struct Node {
int element;
PtrToNode next;
PtrToNode prev;
};

typedef struct ListRecord * List;

struct ListRecord {
PtrToNode head;
PtrToNode tail;
};

List Create() {
List L;
L = (List)malloc(sizeof(struct ListRecord));
L->head = (PtrToNode)malloc(sizeof(struct Node));
L->head->prev = NULL;
L->tail = (PtrToNode)malloc(sizeof(struct Node));
L->head->next = L->tail;
L->tail->prev = L->head;
L->tail->next = NULL;
return L;
}

void Insertion(int x, List L) {
// write your code here
   L->head->element = x;
   struct Node* new_Node = (struct Node*)malloc(sizeof(struct Node));
   new_Node->next = L->head;
   new_Node->prev = NULL;
   L->head = new_Node;
}

int Deletion(List L) {
// write your code here
   if(L->head->next == L->tail)
   {
       return 1e5;
   }
   else
   {
       struct Node* new_Node = L->head->next;
       L->head->next = new_Node->next;
       return 1;
   }
}

Operation Getop() {
char str[7];
scanf("%s", str);
if (strcmp(str, "Push") == 0) {
return 1;
}
else if (strcmp(str, "Pop") == 0) {
return 2;
}
else {
return 3;
}
}

void printList(List L) {
PtrToNode ptr;
ptr = L->head->next;
while(ptr != L->tail) {
printf("%d ", ptr->element);
ptr = ptr->next;
}
}

int main(void) {
int X;
List L;
int flag = 0;

L = Create();
while (!flag) {
switch(Getop()) {
case push:
scanf("%d", &X);
Insertion(X, L);
break;
case pop:
X = Deletion(L);
if (X == 1e5) {
printf("Stack is empty\n");
}
break;
case end:
printList(L);
flag = 1;
break;
}
}
return 0;
}