PTA数据结构与算法题目集（中文）6-2：顺序表操作集

一、题目描述

#include <stdio.h>
#include <stdlib.h>

#define MAXSIZE 5
#define ERROR -1
typedef enum {false, true} bool;
typedef int ElementType;
typedef int Position;
typedef struct LNode *List;
struct LNode {
    ElementType Data[MAXSIZE];
    Position Last; /* 保存线性表中最后一个元素的位置 */
};

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;

    L = MakeEmpty();
    scanf("%d", &N);
    while ( N-- ) {
        scanf("%d", &X);
        if ( Insert(L, X, 0)==false )
            printf(" Insertion Error: %d is not in.\n", X);
    }
    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
            printf("%d is at position %d.\n", X, P);
    }
    scanf("%d", &N);
    while ( N-- ) {
        scanf("%d", &P);
        if ( Delete(L, P)==false )
            printf(" Deletion Error.\n");
        if ( Insert(L, 0, P)==false )
            printf(" Insertion Error: 0 is not in.\n");
    }
    return 0;
}

/* 你的代码将被嵌在这里 */

二、解题代码

List MakeEmpty()
{
    List L = (List)malloc(sizeof(struct LNode));
    if (!L)
        exit(0);
    L->Last = -1;
    return L;
}
Position Find(List L, ElementType X)
{
    if (L->Last == -1)
        return ERROR;
    for (int i = 0; i <= L->Last; i++)
        if (L->Data[i] == X)
            return i;
    return ERROR;
}
bool Insert(List L, ElementType X, Position P)
{
    if (L->Last == MAXSIZE - 1)
    {
        printf("FULL");
        return false;
    }
    if (P > L->Last + 1 || P < 0)
    {
        printf("ILLEGAL POSITION");
        return false;
    }

    for (int i = ++L->Last; i > P; i--)
        L->Data[i] = L->Data[i - 1];
    L->Data[P] = X;
    return true;
}
bool Delete(List L, Position P)
{
    if (P < 0 || P > L->Last)
    {
        printf("POSITION %d EMPTY", P);
        return false;
    }
    for (int i = P; i < L->Last; i++)
        L->Data[i] = L->Data[i + 1];
    L->Last--;
    return true;
}

三、运行结果