算法学习 - 链表的游标实现~ C++

链表的游标实现，就是用另外一种方法来访问链表，模拟游标。

在我学习的理解中，就是创建一个节点数组，模拟内存的排列，然后从其中来申请内存和释放内存。但是实际的内存没有被释放~

下面直接贴代码了：

//
//  main.cpp
//  CursorList
//
//  Created by Alps on 14-7-27.
//  Copyright (c) 2014年 chen. All rights reserved.
//

#include <iostream>

#define CursorSpace 100
#define ElementType int

using namespace std;

typedef int PtrToNode;
typedef PtrToNode List;
typedef PtrToNode Position;

void InitializeCursorList(void);
List MakeEmpty(List L);
int isEmpty(List L);
int isLast(List L, Position P);
void Insert(List L, Position P, ElementType X);
void Delete(List L, ElementType X);
Position Find(List L, ElementType X);
Position FindPrevious(List L, ElementType X);
void DeleteList(List L);

struct Node{
    ElementType X;
    Position Next;
};

struct Node CursorList[CursorSpace];

int isEmpty(List L){
    return CursorList[L].Next == 0;
}

int isLast(List L, Position P){
    return CursorList[P].Next == 0;
}

void InitializeCursorList(void){
    int i = 0;
    for (i = 0; i < CursorSpace; i++) {
        CursorList[i].Next = i + 1;
    }
    CursorList[CursorSpace - 1].Next = 0;
}

Position CursorAlloc(){
    Position P;
    P = CursorList[0].Next;
    CursorList[0].Next = CursorList[P].Next;
    CursorList[P].Next = 0;
    return P;
}

void CursorFree(Position P){
    CursorList[P].Next = CursorList[0].Next;
    CursorList[0].Next = P;
}

Position Find(List L, ElementType X){
    Position P = CursorList[L].Next;
    while (CursorList[P].X != X && P) {
        P = CursorList[P].Next;
    }
    if (P == 0) {
        return false;
    }
    return P;
}

Position FindPrevious(List L, ElementType X){
    Position P = L;
    Position tmp = CursorList[P].Next;
    while (CursorList[tmp].X != X && tmp) {
        tmp = CursorList[tmp].Next;
        P = CursorList[P].Next;
    }
    return P;
}

void Delete(List L, ElementType X){
    Position P = FindPrevious(L, X);
    Position tmp = CursorList[P].Next;
    CursorList[P].Next = CursorList[tmp].Next;
}

void Insert(List L, Position P, ElementType X){
    Position tmp;
    tmp = CursorAlloc();
    CursorList[tmp].X = X;
    CursorList[tmp].Next = CursorList[P].Next;
    CursorList[P].Next = tmp;
}

void DeleteList(List L){
    Position P = CursorList[L].Next;
    Position tmp = P;
    while (tmp != 0) {
        P = CursorList[P].Next;
        CursorFree(tmp);
        if (P == 0) {
            break;
        }
        tmp = P;
    }
    CursorList[L].Next = 0;
}

void Print(List L){
    Position P = CursorList[L].Next;
    while (P != 0) {
        printf("%d ",CursorList[P].X);
        P = CursorList[P].Next;
    }

    printf("\n");
}

int main(int argc, const char * argv[])
{

    printf("start ...\n");
    InitializeCursorList();
    List L = CursorAlloc();
    Insert(L, L, 1);
    Insert(L, L, 3);
    Insert(L, L, 5);
    Insert(L, L, 4);
    Print(L);
    Position P = FindPrevious(L, 3);
    printf("%d\n",P);
    Delete(L, 3);
    Print(L);
    DeleteList(L);
    Print(L);
    return 0;
}

算法是没有问题的，我写完之后测试了每个函数~

有什么问题请留言~

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