Initial commit

Practical-Teaching/Data-Sructure/Big/4/4.3.cpp

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+#include <iostream>
+#include <vector>
+#include <list>
+#include <string>
+#include <cmath>
+
+using namespace std;
+
+const int Base = 31;
+const int TableSize = 1000;
+
+struct Node {
+	string key;
+	int value;
+	Node(string key, int value) : key(key), value(value) {}
+};
+
+class HashTable {
+private:
+	vector<list<Node>> table;
+	int hashFunc(string key) {
+		int hashVal = 0;
+		for (int i = 0; i < key.length(); i++) {
+			hashVal = (hashVal + key[i] * static_cast<long long>(pow(Base, i))) % TableSize;
+		}
+		return hashVal;
+	}
+
+public:
+	HashTable() {
+		table.resize(TableSize);
+	}
+	void insert(string key, int value) {
+		int hashVal = hashFunc(key);
+		for (auto &node : table[hashVal]) {
+			if (node.key == key) {
+				node.value = value;
+				return;
+			}
+		}
+		table[hashVal].push_back(Node(key, value));
+	}
+	int search(string key) {
+		int hashVal = hashFunc(key);
+		for (auto &node : table[hashVal]) {
+			if (node.key == key) {
+				return node.value;
+			}
+		}
+		return -1;
+	}
+	void destroy() {
+		for (auto &bucket : table) {
+			bucket.clear();
+		}
+	}
+};
+
+int main() {
+	HashTable ht;
+	ht.insert("Alice", 1);
+	ht.insert("Bob", 2);
+	cout << "Alice: " << ht.search("Alice") << endl;
+	cout << "Bob: " << ht.search("Bob") << endl;
+	cout << "Charlie: " << ht.search("Charlie") << endl;
+	ht.destroy();
+	return 0;
+}