带头结点的链式表操作集

本题要求实现带头结点的链式表操作集。

函数接口定义：

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

其中List结构定义如下：

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

各个操作函数的定义为：

List MakeEmpty()：创建并返回一个空的线性表；

Position Find( List L, ElementType X )：返回线性表中X的位置。若找不到则返回ERROR；

bool Insert( List L, ElementType X, Position P )：将X插入在位置P指向的结点之前，返回true。如果参数P指向非法位置，则打印“Wrong Position for Insertion”，返回false；

bool Delete( List L, Position P )：将位置P的元素删除并返回true。若参数P指向非法位置，则打印“Wrong Position for Deletion”并返回false。

裁判测试程序样例：

#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;
}

/* 你的代码将被嵌在这里 */

输入样例：

6

12 2 4 87 10 2

4

2 12 87 5

输出样例：

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

List MakeEmpty(){
List L=(List)malloc(sizeof(struct LNode));
L->Next=NULL;
return L;
}
Position Find( List L, ElementType X ){
while (L){
if (L->Data==X) break;
L=L->Next;
}
return L;
}
bool Insert( List L, ElementType X, Position P ){
while (L->Next){
if (L->Next==P) break;
L=L->Next;
}
if (L->Next!=P){
printf("Wrong Position for Insetion\n");
return false;
}
L->Next=(List)malloc(sizeof(struct LNode));
L->Next->Data=X;
L->Next->Next=P;
return true;
}
bool Delete( List L, Position P ){
if (!P){
printf("Wrong Position for Deletion\n");
return false;
}
while (L->Next){
if (L->Next==P) break;
L=L->Next;
}
if (L->Next!=P){
printf("Wrong Position for Deletion\n");
return false;
}
L->Next=P->Next;
return true;
}