字符串处理：

unix的ELF哈希函数

unsigned int ELFHash(char* str){    unsigned int hash = 0;    unsigned int x = 0;    while (*str){        hash = (hash << 4) + (*str++);        if ((x = hash & 0xF0000000L) != 0){            hash ^= (x >> 24);            hash &= ~x;        }    }    return (hash & 0x7FFFFFFF);}

　　

BKDRHash 哈希

unsigned int BKDRHash(char * str)  {      unsigned int seed = 31;//31 131 1313 13131      unsigned int key = 0;      while (*str)          key = key*seed+ *str++;      return key&(0x7fffffff);  }

　　

开散列：

挂链实现：

void Gua(int tmp){    int tp = tmp%N;    if (tp < 0) tp = -tp;    node *t = &H[pos++];    t->num = tmp;    t->next = tagp[tp];    tagp[tp] = t;}int Cha(int tmp){    int tp = tmp%N;    if (tp < 0) tp = -tp;    node *q;    int count = 0;    for (q = tagp[tp]; q != NULL; q = q->next){        if (q->num == tmp) count++;    }    return count;}

　　

　　

vector<>实现：

vector
     
      hash[N];void Gua(int tmp){    int tp = tmp%N;    if (tp < 0) tp = -tp;    hash[tp].push_back(tmp);}int Cha(int tmp){    int tp = tmp%N;    if (tp < 0) tp = -tp;    int count = 0,k;    int sz = hash[tp].size();    for (k = 0; k < sz; ++k){        if (hash[tp][k] == tmp) count++;    }    return count;}