不懂,这个代码哪里错了,怎么改
#include <stdio.h>#include <stdlib.h>
#define ERROR NULL
typedef enum { FALSE, TRUE } BOOL;
typedef int ElementType;
typedef struct LNode *PtrToLNode;
struct LNode {
ElementType Data;
PtrToLNode Next;
};
typedef PtrToLNode Position;
typedef PtrToLNode List;
List MakeEmpty();
Position Find(List L, ElementType X);
bool Insert(List L, ElementType X, Position P);
bool Delete(List L, Position P);
int main()
{
List L;
ElementType X;
Position P;
int N;
bool flag;
L = MakeEmpty();
scanf("%d", &N);
while (N--) {
scanf("%d", &X);
flag = Insert(L, X, L->Next);
if (flag == false) 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 {
flag = Delete(L, P);
printf("%d is found and deleted.\n", X);
if (flag == false)
printf("Wrong Answer.\n");
}
}
flag = Insert(L, X, NULL);
if (flag == false) printf("Wrong Answer\n");
else
printf("%d is inserted as the last element.\n", X);
P = (Position)malloc(sizeof(struct LNode));
flag = Insert(L, X, P);
if (flag == true) printf("Wrong Answer\n");
flag = Delete(L, P);
if (flag == true) printf("Wrong Answer\n");
for (P = L->Next; P; P = P->Next) printf("%d ", P->Data);
return 0;
}
List MakeEmpty(){
List L;
L = (List)malloc(sizeof(struct LNode));
L->Next = NULL;
return L;
}
Position Find(List L, ElementType X){
Position p;
if (L == NULL)
return ERROR;
while (L != NULL){
if (L->Data == X){
p = L;
return p;
}
L = L->Next;
}
return ERROR;
}
bool Insert(List L, ElementType X, Position P){
List tmp = L;
List apply = NULL;
if (L == P){
apply = (List)malloc(sizeof(struct LNode));
apply->Data = X;
apply->Next = P;
tmp = apply;
return tmp;
}
while (L->Next != P && L->Next != NULL){
L = L->Next;
if (L->Next == NULL&&P != NULL){
printf("Wrong Position for Insertion");
return ERROR;
}
else{
apply = (List)malloc(sizeof(struct LNode));
apply->Data = X;
L->Next = apply;
apply->Next = P;
return tmp;
}
}
bool Delete(List L, Position P){
List tmp = L;
if (L == NULL || P == NULL){
printf("Wrong Position for Insertion");
return ERROR;
}
if (L = P){
tmp = L->Next;
free(L);
return tmp;
}
while (L->Next != P&&L->Next != NULL)
L = L->Next;
if (L->Next == NULL){
printf("Wrong Position for Insertion");
return ERROR;
}
else{
L->Next = P->Next;
free(P);
return tmp;
}
}