这是通过哈希函数(hash function)实现的。哈希函数的作用是将一个较大的输入空间映射到一个较小的输出空间。在哈希表中,输入空间是所有key ,输出空间是所有桶(数组索引)。换句话说,输入一个key ,我们可以通过哈希函数得到该key 对应的键值对在数组中的存储位置。 输入一个key ,哈希函数的计算过程分为以下两步。
hash ^= ((hash << 5) + (*str) + (hash >> 2)); } return hash;}/* End Of JS Hash Function */unsigned int PJWHash(char* str, unsigned int len){ const unsigned int BitsInUnsignedInt = (unsigned int)(sizeof(unsigned int) * 8); const unsigned int ThreeQuarters = (unsigned int...
#include <stdio.h> #include <stdlib.h> #define HASH_SIZE 10 int hash_function(int key) { return key % HASH_SIZE; } int main() { int key = 42; int index = hash_function(key); printf("Key %d maps to index %d in the hash table\n", key, index); return 0; } 复制代码 在实...
return hash; } /* End Of RS Hash Function */ unsigned int JSHash(char* str, unsigned int len) { unsigned int hash = 1315423911; unsigned int i = 0; for(i = 0; i < len; str++, i++) { hash ^= ((hash << 5) + (*str) + (hash >> 2)); ...
hash=0;while(*str){hash=hash*a+(*str++);a*=b;}return(hash&0x7FFFFFFF);}// JS Hash Functionunsigned intJSHash(char*str){unsigned int hash=1315423911;while(*str){hash^=((hash<<5)+(*str++)+(hash>>2));}return(hash&0x7FFFFFFF);}// P. J. Weinberger Hash Functionunsigned intP...
hash = hash * a + (*str); a = a * b; return hash; /* End Of RS Hash Function */ unsigned int JSHash(char* str, unsigned int len) unsigned int hash = 1315423911; unsigned int i = 0; for(i = 0; i < len; str++, i++) ...
return hash;} /* End Of JS Hash Function */ unsigned int PJWHash(char* str, unsigned int len){ const unsigned int BitsInUnsignedInt = (unsigned int)(sizeof(unsigned int) * 8);const unsigned int ThreeQuarters = (unsigned int)((BitsInUnsignedInt * 3) / 4);const unsigned int One...
break;}return{};}// 线性探测的删除boolremove(constK&key){size_tindex=hashFunction(key);size_...
mixes of the hash to ensure the last few* bytes are well-incorporated. */h^=h>>13;h*=m;h^=h>>15;return(unsignedint)h;}unsignedintstr_hash(void*key){returnmurmur_hash(key,20);}/* Thomas Wang's 32 bit Mix Function */unsignedintdictIntHashFunction(unsignedintkey){key+=~(key<<...
I can't use boost:hash because I have to stick with C and can't use C++. But, I need to hash a large number (10K to 100k) of tokens strings (5 to 40 bytes length) so that search within those are fastest. MD5, SHA1 or any long hash function seems too heavy for a simple ...