C Programs: Tower of Hanoi and Singly Linked List

Posted on Jan 28, 2026 in Computer Engineering in Computer Engineering

C Programs: Tower of Hanoi and Singly Linked List

Includes: Two C programs: a recursive Tower of Hanoi solver and a singly linked list implementation with stack demo. The original code has been preserved, formatted, and corrected for spelling, grammar, and readability.

Tower of Hanoi – C Program

#include <stdio.h>

void tower_hanoi(int n, char src, char dest, char temp) {
    if (n == 1) {
        printf("\nMove disk %d from peg %c to peg %c", n, src, dest);
        return;
    }
    tower_hanoi(n - 1, src, temp, dest);
    printf("\nMove disk %d from peg %c to peg %c", n, src, dest);
    tower_hanoi(n - 1, temp, dest, src);
}

int main() {
    int n;
    printf("\nEnter the number of disks: ");
    scanf("%d", &n);
    tower_hanoi(n, 'A', 'B', 'C');
    return 0;
}

Singly Linked List – C Program

Implementation includes student records, insert/delete operations, status display, and a stack demo using list operations.

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

struct student {
    char usn[20];
    char name[20];
    char program[20];
    int sem;
    long int phno;
    struct student *link;
};

typedef struct student* STUDENT;
STUDENT start = NULL;

STUDENT create() {
    STUDENT getnode;
    getnode = (STUDENT)malloc(sizeof(struct student));
    if (getnode == NULL) {
        printf("\nMemory could not be allocated!!!");
    }
    printf("\nEnter the usn: ");
    scanf("%s", getnode->usn);
    printf("\nEnter the name: ");
    scanf("%s", getnode->name);
    printf("\nEnter the branch: ");
    scanf("%s", getnode->program);
    printf("\nEnter the sem: ");
    scanf("%d", &getnode->sem);
    printf("\nEnter the phno: ");
    scanf("%ld", &getnode->phno);
    getnode->link = NULL;
    return getnode;
}

void insert_front() {
    STUDENT node;
    node = create();
    if (start == NULL) {
        start = node;
    } else {
        node->link = start;
        start = node;
    }
}

void delete_front() {
    STUDENT temp;
    if (start == NULL) {
        printf("\nList is empty");
    } else {
        temp = start;
        start = temp->link;
        printf("\nThe deleted student usn is %s", temp->usn);
        free(temp);
    }
}

void create_list() {
    int n, i;
    printf("\nEnter the number of students: ");
    scanf("%d", &n);
    for (i = 0; i < n; i++) {
        insert_front();
    }
}

void status() {
    STUDENT temp;
    int count = 0;
    if (start == NULL) {
        printf("\nList is empty");
        return;
    }
    temp = start;
    printf("\nThe student details are: ");
    while (temp != NULL) {
        printf("\n%s\n%s\n%s\n%d\n%ld\n", temp->usn, temp->name, temp->program, temp->sem, temp->phno);
        temp = temp->link;
        count++;
    }
    printf("\nThe number of nodes are: %d", count);
}

void insert_end() {
    STUDENT node, temp;
    node = create();
    if (start == NULL) {
        start = node;
    } else {
        temp = start;
        while (temp->link != NULL) {
            temp = temp->link;
        }
        temp->link = node;
    }
}

void delete_end() {
    STUDENT temp, prev;
    temp = start;
    if (temp == NULL) {
        printf("\nList is empty");
    } else if (temp->link == NULL) {
        printf("\nThe deleted student usn is %s", temp->usn);
        free(temp);
        start = NULL;
    } else {
        while (temp->link != NULL) {
            prev = temp;
            temp = temp->link;
        }
        printf("\nThe deleted student usn is %s", temp->usn);
        free(temp);
        prev->link = NULL;
    }
}

void stack_demo() {
    int ch;
    for (;;) {
        printf("\nSTACK OPERATIONS");
        printf("\n1: Insert End \n2: Delete End \n3: Status of Stack \n4: Exit");
        printf("\nEnter your choice: ");
        scanf("%d", &ch);
        switch (ch) {
            case 1:
                insert_end();
                break;
            case 2:
                delete_end();
                break;
            case 3:
                status();
                break;
            case 4:
                return;
            default:
                printf("\nInvalid choice!!!");
        }
    }
}

int main() {
    int ch;
    for (;;) {
        printf("\nSINGLY LINKED LIST OPERATIONS");
        printf("\n 1: Create List \n 2: Status of List \n 3: Insert End \n 4: Delete End \n 5: Insert Front \n 6: Delete Front \n 7: Stack Demo \n 8: Exit");
        printf("\nEnter your choice: ");
        scanf("%d", &ch);
        switch (ch) {
            case 1:
                create_list();
                break;
            case 2:
                status();
                break;
            case 3:
                insert_end();
                break;
            case 4:
                delete_end();
                break;
            case 5:
                insert_front();
                break;
            case 6:
                delete_front();
                break;
            case 7:
                stack_demo();
                break;
            case 8:
                return 0;
            default:
                printf("\nInvalid choice!!!");
        }
    }
    return 0;
}

Note: Code is preserved and formatted for clarity. Compile each program separately as they both define main().