# PTA 6-2顺序表操作集

xiaoxiao2021-02-28  23

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 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 */ }; 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并返回true。若空间已满，则打印“FULL”并返回false；如果参数P指向非法位置，则打印“ILLEGAL POSITION”并返回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“POSITION P EMPTY”（其中P是参数值）并返回false。

#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 */ 输入样例：

6 1 2 3 4 5 6 3 6 5 1 2 -1 6 输出样例：

FULL Insertion Error: 6 is not in. Finding Error: 6 is not in. 5 is at position 0. 1 is at position 4. POSITION -1 EMPTY Deletion Error. FULL Insertion Error: 0 is not in. POSITION 6 EMPTY Deletion Error. FULL Insertion Error: 0 is not in.

List MakeEmpty(){/* How to define empty? Should it be initialized? */ List L; L = (List)malloc(sizeof(struct LNode)); //Don't forget "struct" unless you already use typedef L->Last = -1; return L; }//L->last: 0 - 4 Position Find(List L,ElementType X){ Position i; for( i = 0; i <= L->Last; i++){ if (L->Data[i] == X) { /* Realize my mistake here, i use MAXSIZE-1 instead of L->Last! A wrong use!*/ break; } } if(i > (L->Last)) return ERROR; else return i; } 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--){ /* put back */ L->Data[i+1] = L->Data[i]; } L->Data[P] = X; L->Last = L->Last + 1; return true; } bool Delete(List L, Position P){ if(P>L->Last|| P<0){ printf("POSITION %d EMPTY",P); return false; }else{ for(Position i=P; i<=L->Last; i++) L->Data[i] = L->Data[i+1]; L->Last = L->Last -1; } return true; }