11-散列1 电话聊天狂人

最新推荐文章于 2024-05-30 09:59:51 发布

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中国大学MOOC-陈越、何钦铭-数据结构-2015秋专栏收录该内容

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本文介绍了一种使用哈希表实现的联系人信息管理系统，通过哈希函数将电话号码映射到特定位置，实现了高效查找、插入和删除操作。系统包括初始化表、销毁表、查找联系人、插入联系人和查找最大联系人数量等功能。

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

typedef struct ListNode *Position;
typedef struct ListNode{
	char PhoneNum[12];
	int cnt;
	Position Next;
} *List;

typedef struct HashTbl{
	int TableSize;
	List *TheLists;//建立一个ListNode的指针数组
} *HashTable;

int NextPrime(int x);
HashTable InitializeTable(int TableSize);
void DestroyTable(HashTable H);
Position Find(char Key[], HashTable H);
void Insert(char Key[], HashTable H);
int Hash(int Key, int TableSize);
void FindMax(HashTable H);

int main(int argc, char const *argv[])
{
	// freopen("test.txt", "r", stdin);
	int N;
	scanf("%d", &N);
	HashTable H = InitializeTable(2 * N);
	char send[12], rec[12];
	for (int i = 0; i < N; i++){
		scanf("%s %s\n", send, rec);
		Insert(send, H), Insert(rec, H);
	}
	FindMax(H);
	DestroyTable(H);
	return 0;
}

int NextPrime(int x)
{
	int i; 
	for (int Next = x; ; Next++){
		for (i = 2; i * i <= Next; i++)
			if (Next % i == 0)
				break;
		if (i * i > Next)
			return Next;
	}
}

HashTable InitializeTable(int TableSize)
{
	HashTable H;
	H = (HashTable)malloc(sizeof(struct HashTbl));
	H->TableSize = NextPrime(TableSize);
	H->TheLists = (List*)malloc(sizeof(List)*H->TableSize);
	for (int i = 0; i != H->TableSize; i++){
		H->TheLists[i] = (List)malloc(sizeof(struct ListNode));
		H->TheLists[i]->Next = NULL;
	}
	return H;
}

void DestroyTable(HashTable H)
{
	for (int i = 0; i < H->TableSize; i++)
		free(H->TheLists[i]);
	free(H->TheLists);
	free(H);
}

Position Find(char Key[], HashTable H)
{
	Position P;
	List L;
	L = H->TheLists[Hash(atoi(Key + 6), H->TableSize)];
	P = L->Next;
	while (P != NULL && strcmp(P->PhoneNum, Key))
		P = P->Next;
	return P;
}

void Insert(char Key[], HashTable H)
{
	Position Pos, Tmp;
	List L = H->TheLists[Hash(atoi(Key + 6), H->TableSize)];
	Pos = Find(Key, H);
	if (Pos == NULL){
		Tmp = (List)malloc(sizeof(struct ListNode));
		strcpy(Tmp->PhoneNum, Key);
		Tmp->cnt = 1;
		Tmp->Next = L->Next;
		L->Next = Tmp;
	} else {
		(Pos->cnt)++;
	}
}

int Hash(int Key, int TableSize)
{
	return (Key % TableSize);
}

void FindMax(HashTable H)
{
	Position P;
	int maxcnt = 0, maxSame = 1;
	char MinPhone[12];
	for (int i = 0; i < H->TableSize; i++){
		P = H->TheLists[i]->Next;
		while (P != NULL){
			if (P->cnt > maxcnt){
				strcpy(MinPhone, P->PhoneNum);
				maxcnt = P->cnt;
				maxSame = 1;
			} else if (P->cnt == maxcnt){
				if (strcmp(MinPhone, P->PhoneNum) > 0)
					strcpy(MinPhone, P->PhoneNum);
				maxSame++;
			}
			P = P->Next;
		}
	}
	printf("%s %d", MinPhone, maxcnt);
	if (maxSame > 1)
		printf(" %d", maxSame);
}