【PTA】6-6 带头结点的链式表操作集 (20分)
【PTA】6-6 带头结点的链式表操作集 (20分)
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：
1 #include <stdio.h> 2 #include <stdlib.h> 3 4 #define ERROR NULL 5 typedef enum {false, true} bool; 6 typedef int ElementType; 7 typedef struct LNode *PtrToLNode; 8 struct LNode { 9 ElementType Data; 10 PtrToLNode Next; 11 }; 12 typedef PtrToLNode Position; 13 typedef PtrToLNode List; 14 15 List MakeEmpty(); 16 Position Find( List L, ElementType X ); 17 bool Insert( List L, ElementType X, Position P ); 18 bool Delete( List L, Position P ); 19 20 int main() 21 { 22 List L; 23 ElementType X; 24 Position P; 25 int N; 26 bool flag; 27 28 L = MakeEmpty(); 29 scanf("%d", &N); 30 while ( N-- ) { 31 scanf("%d", &X); 32 flag = Insert(L, X, L->Next); 33 if ( flag==false ) printf("Wrong Answer\n"); 34 } 35 scanf("%d", &N); 36 while ( N-- ) { 37 scanf("%d", &X); 38 P = Find(L, X); 39 if ( P == ERROR ) 40 printf("Finding Error: %d is not in.\n", X); 41 else { 42 flag = Delete(L, P); 43 printf("%d is found and deleted.\n", X); 44 if ( flag==false ) 45 printf("Wrong Answer.\n"); 46 } 47 } 48 flag = Insert(L, X, NULL); 49 if ( flag==false ) printf("Wrong Answer\n"); 50 else 51 printf("%d is inserted as the last element.\n", X); 52 P = (Position)malloc(sizeof(struct LNode)); 53 flag = Insert(L, X, P); 54 if ( flag==true ) printf("Wrong Answer\n"); 55 flag = Delete(L, P); 56 if ( flag==true ) printf("Wrong Answer\n"); 57 for ( P=L->Next; P; P = P->Next ) printf("%d ", P->Data); 58 return 0; 59 } 60 /* 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 函数实现细节：
1 List MakeEmpty(){ 2 List L=(List)malloc(sizeof(struct LNode)); 3 L->Data=0; 4 L->Next=NULL; 5 return L; 6 } 7 Position Find( List L, ElementType X ){ 8 if (L->Next==NULL)return NULL; 9 L=L->Next; 10 while(L&&L->Data!=X){ 11 L=L->Next; 12 } 13 if(L==NULL){ 14 return NULL; 15 }else if(L->Data==X){ 16 return L; 17 } 18 } 19 20 bool Insert( List L, ElementType X, Position P ){ 21 Position temp=(Position)malloc(sizeof(struct LNode)); 22 if(L->Next==P){ 23 temp->Data=X;temp->Next=P; 24 L->Next=temp; 25 return true; 26 } 27 List Q=L->Next; 28 while(Q->Next!=NULL&&Q->Next!=P)Q=Q->Next; 29 if(P==NULL){ 30 temp->Data=X;temp->Next=NULL; 31 Q->Next=temp; 32 return true; 33 34 }else if(P &&Q->Next==NULL){ 35 printf("Wrong Position for Insertion\n"); 36 return false; 37 } 38 temp->Data=X;temp->Next=P; 39 Q->Next=temp; 40 return true; 41 } 42 43 bool Delete( List L, Position P ){ 44 if (L->Next==NULL)return false; 45 List Q=L->Next; 46 if(P==Q){ 47 L->Next=P->Next; 48 free(P); 49 return true; 50 } 51 while(Q->Next!=P&&Q->Next!=NULL) 52 { 53 Q=Q->Next; 54 } 55 if(Q->Next==NULL){ 56 printf("Wrong Position for Deletion\n"); 57 return false; 58 }else{ 59 Q->Next=P->Next; 60 free(P); 61 return true; 62 } 63 }
