Linked list unable to print all elements-CodePudding

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();
    }
}

CodePudding user response：

temp->next = NULL; is the culprit. It should be temp->next = head;.

Another (more cornercase) issue is that your code fails to check for errors in malloc and scanf.

CodePudding user response：

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;
}