Thread: Help with sorting a Linked List !!

Hey,

I was trying to implement sorting in a linked list. However, when i run the sortList() function the program abruptly terminates.

Here's the complete code

Code:

/*
 * {
 * SingleLinkedList.c
 *
 *  Created on: 28-Nov-2014
 *      Author: bennet
 */
#define NULL 0
#include<stdio.h>
#include<stdlib.h>
struct node {
    int data;
    struct node *link;
}*start;
void menu() {
    printf("1. Insert at End\n");
    printf("2. Insert at head\n");
    printf("3. Display\n");
    printf("4. Delete\n");
    printf("5. Sort Ascending\n");
    printf("6. Build List\n");
}
void sortList(struct node **head_ref) {
    struct node *curr = *head_ref;
    struct node *next;
    while (curr != NULL) {
        {
            next = curr->link;
            if(curr->data < next->data)
            {
                int temp = curr->data;
                curr->data = next->data;
                next->data = temp;
            }
        }
        curr = curr->link;
        }
    }


void add(struct node **head_ref, int data) {
    struct node *temp = (struct node *) malloc(sizeof(struct node));
    struct node *start = *head_ref;
    if (*head_ref == NULL) {
        temp->data = data;
        temp->link = NULL;
        *head_ref = temp;
    } else {
        while (start->link != NULL) {
            start = start->link;
        }
        temp->data = data;
        temp->link = NULL;
        start->link = temp;
    }
    printf("Added the data %d\n", data);
}
void insertAtHead(struct node **head_ref, int value) {


    struct node *temp = (struct node *) malloc(sizeof(struct node));
    temp->data = value;
    temp->link = *head_ref;
    *head_ref = temp;
}
void delete(struct node **start, int delete) {
    struct node *temp = *start;
    while (temp->link != NULL) {
        if (temp->link->data == delete) {
            temp->link = temp->link->link;
            free(temp->link);
            break;
        } else
            temp = temp->link;
    }
}
void display(struct node **head_ref) {
    struct node *temp = *head_ref;
    while (temp != NULL) {
        printf("%d\n", temp->data);
        temp = temp->link;
    }


}
void buildList(struct node **head_ref) {
    int i;
    for (i = 0; i < 10; i++) {
        add(&(*head_ref), i);
    }


}
int main() {
    int choice;
    start = NULL;
    char charInput;
    do {
        menu();
        scanf("%d", &choice);
        switch (choice) {
        case 1: {
            int datas;
            scanf("%d", &datas);
            add(&start, datas);
            break;
        }
        case 3:
            display(&start);
            break;
        case 2: {
            int datas;
            scanf("%d", &datas);
            insertAtHead(&start, datas);
            break;
        }
        case 4: {
            int datas;
            scanf("%d", &datas);
            delete(&start, datas);
            break;
        }
        case 5: {
            sortList(&start);
            break;
        }
        case 6: {
            buildList(&start);
            break;
        }
}
        printf("Want to Continue(y/n)?\n");
        scanf(" %c", &charInput);
    } while (charInput == 'y' || charInput == 'Y');
    return 0;
}

Any suggestion to resolve this will be very helpful . Thanks !!