1-4 linked list operation set (10 points)

Function interface definition:

Position Find( List L, ElementType X );
List Insert( List L, ElementType X, Position P );
List Delete( List L, Position P );

The List structure is defined as follows:

typedef struct LNode *PtrToLNode;
struct LNode {
ElementType Data;
PtrToLNode Next;
};
typedef PtrToLNode Position;
typedef PtrToLNode List;

Each operation function is defined as:

Position Find (List L, Element Type X): Returns the location where X first appeared in a linear table. If not found, return to ERROR.

List Insert (List L, Element Type X, Position P): Insert X into the list header before the node to which location P points. If parameter P points to an illegal location, print "Wrong Position for Insertion" and return ERROR.

List Delete (List L, Position P): Delete the element of position P and return to the header of the linked list. If parameter P points to an illegal location, print "Wrong Position for Deletion" and return ERROR.

Examples of referee testing procedures:

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

#define ERROR NULL
typedef int ElementType;
typedef struct LNode *PtrToLNode;
struct LNode {
ElementType Data;
PtrToLNode Next;
};
typedef PtrToLNode Position;
typedef PtrToLNode List;

Position Find( List L, ElementType X );
List Insert( List L, ElementType X, Position P );
List Delete( List L, Position P );

int main()
{
List L;
ElementType X;
Position P, tmp;
int N;

L = NULL;
scanf("%d", &N);
while ( N-- ) {
scanf("%d", &X);
L = Insert(L, X, L);
if ( L==ERROR ) printf("Wrong Answer\n");
}
scanf("%d", &N);
while ( N-- ) {
scanf("%d", &X);
P = Find(L, X);
if ( P == ERROR )
printf("Finding Error: %d is not in.\n", X);
else {
L = Delete(L, P);
printf("%d is found and deleted.\n", X);
if ( L==ERROR )
printf("Wrong Answer or Empty List.\n");
}
}
L = Insert(L, X, NULL);
if ( L==ERROR ) printf("Wrong Answer\n");
else
printf("%d is inserted as the last element.\n", X);
P = (Position)malloc(sizeof(struct LNode));
tmp = Insert(L, X, P);
if ( tmp!=ERROR ) printf("Wrong Answer\n");
tmp = Delete(L, P);
if ( tmp!=ERROR ) printf("Wrong Answer\n");
for ( P=L; P; P = P->Next ) printf("%d ", P->Data);
return 0;
}

/* Your code will be embedded here */

6
12 2 4 87 10 2
4
2 12 87 5

Output sample:

2 is found and deleted.
12 is found and deleted.
87 is found and deleted.
Finding Error: 5 is not in.
5 is inserted as the last element.
Wrong Position for Insertion
Wrong Position for Deletion
10 4 2 5

Position Find(List L,ElementType X){
List F=L;
while(F){
if(F->Data==X)return F;
F=F->Next;
}
return ERROR;
}
List Insert(List L,ElementType X,Position P){
}
while(L){
if(L->Next==P)break;
L=L->Next;
}
if(!L){printf("Wrong Position for Insertion\n");
return ERROR;
}

L->Next=(List)malloc(sizeof(struct LNode));
L->Next->Data=X;
L->Next->Next=P;

}
List Delete(List L,Position P){
if(L==P){L=L->Next;
return L;
}