4-5 链式表操作集 (20分)

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本题要求实现链式表的操作集。
函数接口定义：

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

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

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

List Delete( List L, Position P )：将位置P的元素删除并返回链表的表头。若参数P指向非法位置，则打印“Wrong Position for Deletion”并返回ERROR。
裁判测试程序样例：

#include <stdio.h>#include <stdlib.h>#define ERROR NULLtypedef 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;}/* 你的代码将被嵌在这里 */

输入样例：

612 2 4 87 10 242 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 InsertionWrong Position for Deletion10 4 2 5

点击访问 PTA测验

#include <stdio.h>#include <stdlib.h>/*评测结果时间  结果  得分  题目  编译器 用时（ms）  内存（MB）  用户2016-02-06 20:57    答案正确    20  4-5 gcc 2   1   569985011测试点结果测试点 结果  得分/满分   用时（ms）  内存（MB）测试点1    答案正确    12/12       2       1测试点2    答案正确    4/4         1       1测试点3    答案正确    4/4         1       1*/#define ERROR NULLtypedef 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;}/* 你的代码将被嵌在这里 */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){    List head=L;    if(L==P){head=(List)malloc(sizeof(struct LNode));    head->Data=X;head->Next=P;return head;    }    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;return head;    }List Delete(List L,Position P){if(L==P){L=L->Next;    return L;}    List head=L;while(L){    if(L->Next==P)break;    L=L->Next;}if(!L){printf("Wrong Position for Deletion\n");    return ERROR;}L->Next=P->Next;free(P);    return head;}