69 lines
1.4 KiB
C
69 lines
1.4 KiB
C
/**
|
|
* File: simple_hash.c
|
|
* Created Time: 2023-09-09
|
|
* Author: Gonglja (glj0@outlook.com)
|
|
*/
|
|
|
|
#include "../utils/common.h"
|
|
|
|
/* Additive hash */
|
|
int addHash(char *key) {
|
|
long long hash = 0;
|
|
const int MODULUS = 1000000007;
|
|
for (int i = 0; i < strlen(key); i++) {
|
|
hash = (hash + (unsigned char)key[i]) % MODULUS;
|
|
}
|
|
return (int)hash;
|
|
}
|
|
|
|
/* Multiplicative hash */
|
|
int mulHash(char *key) {
|
|
long long hash = 0;
|
|
const int MODULUS = 1000000007;
|
|
for (int i = 0; i < strlen(key); i++) {
|
|
hash = (31 * hash + (unsigned char)key[i]) % MODULUS;
|
|
}
|
|
return (int)hash;
|
|
}
|
|
|
|
/* XOR hash */
|
|
int xorHash(char *key) {
|
|
int hash = 0;
|
|
const int MODULUS = 1000000007;
|
|
|
|
for (int i = 0; i < strlen(key); i++) {
|
|
hash ^= (unsigned char)key[i];
|
|
}
|
|
return hash & MODULUS;
|
|
}
|
|
|
|
/* Rotational hash */
|
|
int rotHash(char *key) {
|
|
long long hash = 0;
|
|
const int MODULUS = 1000000007;
|
|
for (int i = 0; i < strlen(key); i++) {
|
|
hash = ((hash << 4) ^ (hash >> 28) ^ (unsigned char)key[i]) % MODULUS;
|
|
}
|
|
|
|
return (int)hash;
|
|
}
|
|
|
|
/* Driver Code */
|
|
int main() {
|
|
char *key = "Hello 算法";
|
|
|
|
int hash = addHash(key);
|
|
printf("Additive hash value = %d\n", hash);
|
|
|
|
hash = mulHash(key);
|
|
printf("Multiplicative hash value = %d\n", hash);
|
|
|
|
hash = xorHash(key);
|
|
printf("XOR hash value = %d\n", hash);
|
|
|
|
hash = rotHash(key);
|
|
printf("Rotational hash value = %d\n", hash);
|
|
|
|
return 0;
|
|
}
|