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67 lines
1.4 KiB
67 lines
1.4 KiB
/**
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* File: simple_hash.cpp
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* Created Time: 2023-06-21
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* Author: krahets (krahets@163.com)
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*/
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#include "../utils/common.hpp"
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/* Additive hash */
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int addHash(string key) {
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long long hash = 0;
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const int MODULUS = 1000000007;
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for (unsigned char c : key) {
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hash = (hash + (int)c) % MODULUS;
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}
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return (int)hash;
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}
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/* Multiplicative hash */
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int mulHash(string key) {
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long long hash = 0;
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const int MODULUS = 1000000007;
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for (unsigned char c : key) {
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hash = (31 * hash + (int)c) % MODULUS;
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}
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return (int)hash;
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}
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/* XOR hash */
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int xorHash(string key) {
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int hash = 0;
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const int MODULUS = 1000000007;
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for (unsigned char c : key) {
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hash ^= (int)c;
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}
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return hash & MODULUS;
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}
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/* Rotational hash */
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int rotHash(string key) {
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long long hash = 0;
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const int MODULUS = 1000000007;
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for (unsigned char c : key) {
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hash = ((hash << 4) ^ (hash >> 28) ^ (int)c) % MODULUS;
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}
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return (int)hash;
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}
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/* Driver Code */
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int main() {
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string key = "Hello algorithm";
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int hash = addHash(key);
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cout << "Additive hash value is " << hash << endl;
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hash = mulHash(key);
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cout << "Multiplicative hash value is " << hash << endl;
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hash = xorHash(key);
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cout << "XOR hash value is " << hash << endl;
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hash = rotHash(key);
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cout << "Rotational hash value is " << hash << endl;
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return 0;
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}
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