Traverse the Tree Recursively
#include
#include
#include
struct node
{
int a;
struct node *left;
struct node *right;
};
void generate(struct node **, int);
void infix(struct node *);
void postfix(struct node *);
void prefix(struct node *);
void delete(struct node **);
int main()
{
struct node *head = NULL;
int choice = 0, num, flag = 0, key;
do
{
printf("\nEnter your choice:\n1. Insert\n2. Traverse via infix\n3.Traverse via prefix\n4. Traverse via postfix\n5. Exit\nChoice: ");
scanf("%d", &choice);
switch(choice)
{
case 1:
printf("Enter element to insert: ");
scanf("%d", &num);
generate(&head, num);
break;
case 2:
infix(head);
break;
case 3:
prefix(head);
break;
case 4:
postfix(head);
break;
case 5:
delete(&head);
printf("Memory Cleared\nProgram terminated\n");
break;
default: printf("Not a valid input, try again\n");
}
} while (choice != 5);
return 0;
}
void generate(struct node **head, int num)
{
struct node *temp = *head, *prev = *head;
if (*head == NULL)
{
*head = (struct node *)malloc(sizeof(struct node));
(*head)->a = num;
(*head)->left = (*head)->right = NULL;
}
else
{
while (temp != NULL)
{
if (num > temp->a)
{
prev = temp;
temp = temp->right;
}
else
{
prev = temp;
temp = temp->left;
}
}
temp = (struct node *)malloc(sizeof(struct node));
temp->a = num;
if (num >= prev->a)
{
prev->right = temp;
}
else
{
prev->left = temp;
}
}
}
void infix(struct node *head)
{
if (head)
{
infix(head->left);
printf("%d ", head->a);
infix(head->right);
}
}
void prefix(struct node *head)
{
if (head)
{
printf("%d ", head->a);
prefix(head->left);
prefix(head->right);
}
}
void postfix(struct node *head)
{
if (head)
{
postfix(head->left);
postfix(head->right);
printf("%d ", head->a);
}
}
void delete(struct node **head)
{
if (*head != NULL)
{
if ((*head)->left)
{
delete(&(*head)->left);
}
if ((*head)->right)
{
delete(&(*head)->right);
}
free(*head);
}
}
Output
Enter your choice:
1. Insert
2. Traverse via infix
3. Traverse via prefix
4. Traverse via postfix
5. Exit
Choice: 1
Enter element to insert: 5
Reverse a Stack using Recursion
#include
#include
#include
struct node
{
int a;
struct node *next;
};
void generate(struct node **);
void display(struct node *);
void stack_reverse(struct node **, struct node **);
void delete(struct node **);
int main()
{
struct node *head = NULL;
generate(&head);
printf("\nThe sequence of contents in stack\n");
display(head);
printf("\nInversing the contents of the stack\n");
if (head != NULL)
{
stack_reverse(&head, &(head->next));
}
printf("\nThe contents in stack after reversal\n");
display(head);
delete(&head);
return 0;
}
void stack_reverse(struct node **head, struct node **head_next)
{
struct node *temp;
if (*head_next != NULL)
{
temp = (*head_next)->next;
(*head_next)->next = (*head);
*head = *head_next;
*head_next = temp;
stack_reverse(head, head_next);
}
}
void display(struct node *head)
{
if (head != NULL)
{
printf("%d ", head->a);
display(head->next);
}
}
void generate(struct node **head)
{
int num, i;
struct node *temp;
printf("Enter length of list: ");
scanf("%d", &num);
for (i = num; i > 0; i--)
{
temp = (struct node *)malloc(sizeof(struct node));
temp->a = i;
if (*head == NULL)
{
*head = temp;
(*head)->next = NULL;
}
else
{
temp->next = *head;
*head = temp;
}
}
}
void delete(struct node **head)
{
struct node *temp;
while (*head != NULL)
{
temp = *head;
*head = (*head)->next;
free(temp);
}
}
Output
Enter length of list: 10
The sequence of contents in stack
1 2 3 4 5 6 7 8 9 10
Inversing the contents of the stack
The contents in stack after reversal
10 9 8 7 6 5 4 3 2 1
No comments:
Post a Comment