clinked-listprintfinsertion

Linked list unable to print all elements


I'm trying to print the linked list to which I prompt for user input. This code below is not printing the whole list, only the last element at a time. I don't seem to find the bug. Can you please take a look at it?

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

struct Node {
    int data;
    struct Node *next;
};

struct Node *head;

void Insert(int x) {
    struct Node *temp = (struct Node *)malloc(sizeof(struct Node));
    temp->data = x;
    temp->next = NULL;
    head = temp;
};

void Print() {
    struct Node *temp = head;
    printf("Linked list is: ");
    while (temp != NULL) {
        printf("%d ", temp->data);
        temp = temp->next;
    }
    printf("\n");
};

int main() {
    head = NULL;
    int i, x;
    for (i = 1; i <= 10; i++) {
        if (i == 1) {
            printf("Enter 1st number: \n");
        } else if (i == 2) {
            printf("Enter 2nd number: \n");
        } else {
            printf("Enter %dth number: \n", i);
        }
        scanf("%d", &x);
        Insert(x);
        Print();
    }
}

Solution

  • When you insert the new node, you do not link the rest of the list, instead of temp->next = NULL; you should write

        temp->next = head;
    

    To ensure defined behavior, you should check for memory allocation failure and invalid input.

    Also remove the dummy ; after the function bodies.

    Here is a modified version:

    #include <stdio.h>
    #include <stdlib.h>
    
    struct Node {
        int data;
        struct Node *next;
    };
    
    struct Node *head;
    
    int Insert(int x) {
        struct Node *temp = malloc(sizeof(*temp));
        if (temp) {
            temp->data = x;
            temp->next = head;
            head = temp;
            return 1;
        } else {
            return 0;
        }
    }
    
    void Print(void) {
        struct Node *temp = head;
        printf("Linked list is: ");
        while (temp != NULL) {
            printf("%d ", temp->data);
            temp = temp->next;
        }
        printf("\n");
    }
    
    int main() {
        static char suffix[4][3] = { "th", "st", "nd", "rd" };
        int i, x;
        for (i = 1; i <= 10; i++) {
            int suff = (i >= 1 && i <= 3) ? i : 0;
            printf("Enter %d%s number:\n", i, suffix[suff]);
            if (scanf("%d", &x) != 1) {
                fprintf(stderr, "invalid or missing input\n");
                break;
            }
            if (!Insert(x)) {
                fprintf(stderr, "cannot allocate memory for Node\n");
                return 1;
            }
            Print();
        }
        return 0;
    }