編譯環境：vs2015

實現100以內完全平方數的雜湊表建立，當然更多數也是可以的……基本是例題難度，寫了好大一天。

定義結構體:

主要實現函式：

// ConsoleApplication5.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
//
//  main.c
//  t12_23-c
//
//  Created by 04 on 16/12/22.
//  Copyright  2016年 feng. All rights reserved.
//

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

struct ListNode;
typedef struct ListNode *Position;
struct HashTb1;
typedef struct HashTb1 *HashTable;
typedef int ElementType;
int nextPrime(int x);
//表節點 Next塞入第一個元素
struct ListNode
{
    ElementType element;
    Position next;
};

typedef Position  List;

struct HashTb1
{
    int tableSize;
    List * TheList;
};

//初始化
HashTable InitializeTable(int TableSize);
//銷燬表
void DestroyTable(HashTable H);
//找到表節點
Position Find(ElementType key, HashTable H);
//插入元素
void Insert(ElementType key, HashTable H);
//找到首個表節點的位置
int  Hash(ElementType key, int HashSize);
//遍歷
void visited(HashTable H);

int main(int argc, const char * argv[]) {
    //test
    int TableSize = 10;
    HashTable H = InitializeTable(TableSize);
    for (int i = 0; i <= 10; i++)
    {
        int j = i*i;
        Insert(j, H);
    }
    visited(H);
    DestroyTable(H);
    visited(H);
    DestroyTable(H);
}

HashTable InitializeTable(int TableSize)
{
    //尋找質數
    HashTable H;
    H = (HashTable)malloc(sizeof(struct HashTb1));
    if (H == NULL)
    {
        printf("Out of space!");
    }
    H->tableSize = nextPrime(TableSize);
    H->TheList = (List *)malloc(H->tableSize*(sizeof(struct ListNode)));
    for (int i = 0; i < H->tableSize; i++)
    {
        H->TheList[i] = (struct ListNode*)malloc(sizeof(struct ListNode));
        if (H->TheList[i] == NULL)
        {
            printf("不存在!\n");
        }
        else {
            H->TheList[i]->element = i;
            H->TheList[i]->next = NULL;
        }
    }
    return H;
}

void DestroyTable(HashTable H)
{

    if (H->tableSize == 0)
    {
        printf("無需銷燬，表不存在!\n");
    }
    else
    {
        for (int i = 0; i < H->tableSize; i++)
        {
            Position p = H->TheList[i];
            Position q;
            while (p->next != NULL)
            {
                q = p;
                p = p->next;
                free(q);
            }
        }
        H->tableSize = 0;
        H->TheList = NULL;
    }
}

Position Find(ElementType key, HashTable H)
{
    Position p = H->TheList[Hash(key, H->tableSize)];
    while (p != NULL)
    {
        if (p->element != key) { p = p->next; }
        else {
            break;
        }
    }
    if (p == NULL)
    {
        return NULL;
    }
    else
    {
        return p;
    }
}

//插入
void Insert(ElementType key, HashTable H)
{
    if (H->tableSize != 0)
    {
        Position p = Find(key, H);
        Position NewCell;
        List L = H->TheList[Hash(key, H->tableSize)];
        if (p == NULL)
        {
            NewCell = (struct ListNode*)malloc(sizeof(struct ListNode));
            NewCell->next = L->next;
            NewCell->element = key;
            L->next = NewCell;
        }
        else
        {
            p->next = (struct ListNode *)malloc(sizeof(struct ListNode));
            p->next->element = p->element;
            p->next->next = NULL;
        }
    }
    else { printf("沒東西.\n"); }
}

void visited(HashTable H)
{
    if (H->tableSize == 0)
    {
        printf("無表!\n");
    }
    else
    {
        for (int i = 0; i < H->tableSize; i++)
        {
            Position p = H->TheList[i];
            while (p != NULL)
            {
                printf("%d\t", p->element);
                p = p->next;
            }
            printf("\n");
        }
    }
}


int Hash(ElementType key, int HashSize)
{
    int NewKey = key%HashSize;
    return NewKey;
}

//求下一個質數 質數大小是比較易存的
int nextPrime(int x)
{
    int flag = 0;
    for (int i = x; flag == 0; i++)
    {
        int j = 2;
        for (; j <= sqrt(i); j++)
        {
            if (i%j == 0)
            {
                break;
            }
        }
        if (j == (int)sqrt(i) + 1)
        {
            flag = i;
        }
    }
    return flag;
}