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67 lines
1.5 KiB
67 lines
1.5 KiB
/**
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* File: simple_hash.cs
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* Created Time: 2023-06-26
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* Author: hpstory (hpstory1024@163.com)
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*/
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namespace hello_algo.chapter_hashing;
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public class simple_hash {
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/* 加法哈希 */
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int AddHash(string key) {
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long hash = 0;
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const int MODULUS = 1000000007;
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foreach (char c in key) {
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hash = (hash + c) % MODULUS;
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}
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return (int)hash;
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}
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/* 乘法哈希 */
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int MulHash(string key) {
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long hash = 0;
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const int MODULUS = 1000000007;
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foreach (char c in key) {
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hash = (31 * hash + c) % MODULUS;
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}
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return (int)hash;
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}
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/* 异或哈希 */
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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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foreach (char c in key) {
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hash ^= c;
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}
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return hash & MODULUS;
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}
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/* 旋转哈希 */
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int RotHash(string key) {
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long hash = 0;
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const int MODULUS = 1000000007;
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foreach (char c in key) {
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hash = ((hash << 4) ^ (hash >> 28) ^ c) % MODULUS;
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}
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return (int)hash;
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}
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[Test]
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public void Test() {
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string key = "Hello 算法";
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int hash = AddHash(key);
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Console.WriteLine("加法哈希值为 " + hash);
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hash = MulHash(key);
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Console.WriteLine("乘法哈希值为 " + hash);
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hash = XorHash(key);
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Console.WriteLine("异或哈希值为 " + hash);
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hash = RotHash(key);
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Console.WriteLine("旋转哈希值为 " + hash);
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}
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}
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