【数据结构-查找】哈希表的应用

#include<stdio.h>

#include<conio.h>

#define HASH_LEN 50 //哈希表的长度

#define M 47 //随机数

#define NAME_NO 30 //人名的个数

typedef struct

{

char *py; //名字的拼音

int k; //拼音所对应的整数

}NAME;

NAME NameList[HASH_LEN]; //全局变量NAME

typedef struct //哈希表

{

char *py; //名字的拼音

int k; //拼音所对应的整数

int si; //查找长度

}HASH;

HASH HashList[HASH_LEN]; //全局变量HASH

void InitNameList() //姓名（结构体数组）初始化

{

char *f;

int r, s0, i;

NameList[0].py = "wanghui";

NameList[1].py = "mayuelong";

NameList[2].py = "chenzhicheng";

NameList[3].py = "sunpeng";

NameList[4].py = "zengqinghui";

NameList[5].py = "liqingbo";

NameList[6].py = "liujunpeng";

NameList[7].py = "jiangquanlei";

NameList[8].py = "xingzhengchuan";

NameList[9].py = "luzhaoqian";

NameList[10].py = "gaowenhu";

NameList[11].py = "zhuhaoyin";

NameList[12].py = "chenlili";

NameList[13].py = "wuyunyun";

NameList[14].py = "huangjuanxia";

NameList[15].py = "wangyan";

NameList[16].py = "zhoutao";

NameList[17].py = "jiangzhenyu";

NameList[18].py = "liuxiaolong";

NameList[19].py = "wangziming";

NameList[20].py = "fengjunbo";

NameList[21].py = "lilei";

NameList[22].py = "wangjia";

NameList[23].py = "zhangjianguo";

NameList[24].py = "zhuqingqing";

NameList[25].py = "huangmin";

NameList[26].py = "haoyuhan";

NameList[27].py = "zhoutao";

NameList[28].py = "zhujiang";

NameList[29].py = "lixiaojun";

for (i = 0; i<NAME_NO; i++)

{

s0 = 0;

f = NameList[i].py;

for (r = 0; *(f + r) != '\0'; r++)

/* 方法：将字符串的各个字符所对应的ASCII码相加，所得的整数做为哈希表的关键字*/

s0 = *(f + r) + s0;

NameList[i].k = s0;

}

}

void CreateHashList() //建立哈希表

{

int i;

for (i = 0; i<HASH_LEN; i++)

{

HashList[i].py = "";

HashList[i].k = 0;

HashList[i].si = 0;

}

for (i = 0; i<HASH_LEN; i++)

{

int sum = 0;

int adr = (NameList[i].k) % M; //哈希函数

int d = adr;

if (HashList[adr].si == 0) //如果不冲突

{

HashList[adr].k = NameList[i].k;

HashList[adr].py = NameList[i].py;

HashList[adr].si = 1;

}

else //冲突

{

do

{

d = (d + NameList[i].k % 10 + 1) % M; //伪随机探测再散列法处理冲突

sum = sum + 1; //查找次数加1

} while (HashList[d].k != 0);

HashList[d].k = NameList[i].k;

HashList[d].py = NameList[i].py;

HashList[d].si = sum + 1;

}

}

}

void FindList() //查找

{

char name[20] = { 0 };

int s0 = 0, r, sum = 1, adr, d;

printf("\n请输入姓名的拼音:");

scanf("%s", name);

for (r = 0; r<20; r++) //求出姓名的拼音所对应的整数(关键字)

s0 += name[r];

adr = s0%M; //使用哈希函数

d = adr;

if (HashList[adr].k == s0) //分3种情况进行判断

printf("\n姓名:%s 关键字:%d 查找长度为: 1", HashList[d].py, s0);

else if (HashList[adr].k == 0)

printf("无此记录!");

else

{

int g = 0;

do

{

d = (d + s0 % 10 + 1) % M; //伪随机探测再散列法处理冲突

sum = sum + 1;

if (HashList[d].k == 0)

{

printf("无此记录! ");

g = 1;

}

if (HashList[d].k == s0)

{

printf("\n姓名:%s 关键字:%d 查找长度为:%d", HashList[d].py, s0, sum);

g = 1;

}

} while (g == 0);

}

}

void Display() // 显示哈希表

{

int i;

float average = 0;

printf("\n\n地址\t关键字\t\t搜索长度\tH(key)\t 姓名\n"); //显示的格式

for (i = 0; i<50; i++)

{

printf("%d ", i);

printf("\t%d ", HashList[i].k);

printf("\t\t%d ", HashList[i].si);

printf("\t\t%d ", HashList[i].k%M);

printf("\t %s ", HashList[i].py);

printf("\n");

}

for (i = 0; i<HASH_LEN; i++)

average += HashList[i].si;

average /= NAME_NO;

printf("\n\n平均查找长度：ASL(%d)=%f \n\n", NAME_NO, average);

}

void main()

{

char ch1;

printf("\n 哈希表的建立和查找\n");

printf(" *-------------------------------------------*\n");

printf(" | D. 显示哈希表 |\n");

printf(" | F. 查找 |\n");

printf(" | Q. 退出 |\n");

printf(" *-------------------------------------------*\n");

InitNameList();

CreateHashList();

while (1)

{

printf("\n Option-:");

fflush(stdin);

ch1 = getchar();

if (ch1 == 'D' || ch1 == 'd')

Display();

else if (ch1 == 'F' || ch1 == 'f')

FindList();

else if (ch1 == 'Q' || ch1 == 'q')

return;

else

{

printf("\n请输入正确的选择!");

}

}

}