PTA带头结点的链式表操作集
6-2 带头结点的链式表操作集 (20 分)
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
1 List MakeEmpty(){
2    List l=(List)malloc(sizeof(struct LNode));
3    l->Data=0;
4    l->Next=NULL;
5return l;
6 }
7
8 Position Find( List L, ElementType X ){
9    Position p=(Position)malloc(sizeof(Position));
10while(L){
11if(L->Data==X){
12            p=L;
13return p;
14        }
15        L=L->Next;
16    }
17return ERROR;
18 }//返回线性表中X的位置。若不到则返回ERROR；
19
20bool Insert( List L, ElementType X, Position P ){
21
22    Position n=(Position)malloc(sizeof(struct LNode));
23    n->Data=X;
24
25while(L){
26if(L->Next==P){
27            n->Next=P;
28            L->Next=n;
29return true;
30        }
31        L=L->Next;
32    }
33 printf("Wrong Position for Insertion\n");
34return false;
35 }//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；36
37bool Delete( List L, Position P ){
38
39while(L){
40if(L->Next==P){
41            L->Next=P->Next;
42return true;
43        }
44        L=L->Next;
45    }
怎么用printf输出bool函数值46    printf("Wrong Position for Deletion\n");
47return false;
48 }//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。