C Program to Check if Two Lists are Equal

This C Program checks whether 2 lists are the same. The lists are said to be same if they contain same elements at same position.

Here is source code of the C Program to check whether 2 lists are the same. The C program is successfully compiled and run on a Linux system. The program output is also shown below.

```
/*
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 * C Program to Check whether 2 Lists are Same

```
 */
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#include <stdio.h>
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```
#include <stdlib.h>
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```
 
```
```
struct node
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```
{
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    int num;
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    struct node *next;
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};
```
```
 
```
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void feedmember(struct node **);
```

int compare (struct node *, struct node *);

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void release(struct node **);
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```
 
```
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int main()
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```
{
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    struct node *p = NULL;
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    struct node *q = NULL;
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    int result;
```
```
 
```

    printf("Enter data into first list\n");

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    feedmember(&p);
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    printf("Enter data into second list\n");

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    feedmember(&q);
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    result = compare(p, q);
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    if (result == 1)
```
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    {
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        printf("The 2 list are equal.\n");

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    }
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```
    else
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```
    {
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        printf("The 2 lists are unequal.\n");

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    }
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    release (&p);
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    release (&q);
```
```
 
```
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    return 0;
```
```
}
```
```
 
```

int compare (struct node *p, struct node *q)

```
{
```
```
    while (p != NULL && q != NULL)
```
```
    {
```
```
        if (p->num != q-> num)
```
```
        {
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            return 0;
```
```
        }
```
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        else
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```
        {
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            p = p->next;
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            q = q->next;
```
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        }
```
```
    }
```
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    if (p != NULL || q != NULL)
```
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    {
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        return 0;
```
```
    }
```
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    else
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```
    {
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        return 1;
```
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    }
```
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}
```
```
 
```
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void feedmember (struct node **head)
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```
{
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    int c, ch;
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    struct node *temp;
```
```
 
```
```
    do
```
```
    {
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```
        printf("Enter number: ");
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        scanf("%d", &c);
```

        temp = (struct node *)malloc(sizeof(struct node));

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        temp->num = c;
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        temp->next = *head;
```
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        *head = temp;
```

        printf("Do you wish to continue [1/0]: ");

```
        scanf("%d", &ch);
```
```
    }while (ch != 0);
```
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    printf("\n");
```
```
}
```
```
 
```
```
void release (struct node **head)
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```
{
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```
    struct node *temp = *head;
```
```
 
```
```
    while ((*head) != NULL)
```
```
    {
```
```
        (*head) = (*head)->next;
```
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        free(temp);
```
```
        temp = *head;
```
```
    }
```
```
}
```

$ cc checklinklist.c 
$ ./a.out
Enter data into first list
Enter number: 12
Do you wish to continue [1/0]: 1
Enter number: 3
Do you wish to continue [1/0]: 1
Enter number: 28
Do you wish to continue [1/0]: 1
Enter number: 9
Do you wish to continue [1/0]: 0
 
Enter data into second list
Enter number: 12
Do you wish to continue [1/0]: 1
Enter number: 3
Do you wish to continue [1/0]: 1
Enter number: 28
Do you wish to continue [1/0]: 1
Enter number: 9
Do you wish to continue [1/0]: 0
 
The 2 list are equal.