125 lines
3.1 KiB
Rust
125 lines
3.1 KiB
Rust
/**
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* File: array_hash_map.rs
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* Created Time: 2023-2-18
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* Author: xBLACICEx (xBLACKICEx@outlook.com)
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*/
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/* Key-value pair */
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#[derive(Debug, Clone, PartialEq)]
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pub struct Pair {
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pub key: i32,
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pub val: String,
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}
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/* Hash table based on array implementation */
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pub struct ArrayHashMap {
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buckets: Vec<Option<Pair>>,
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}
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impl ArrayHashMap {
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pub fn new() -> ArrayHashMap {
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// Initialize an array, containing 100 buckets
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Self {
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buckets: vec![None; 100],
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}
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}
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/* Hash function */
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fn hash_func(&self, key: i32) -> usize {
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key as usize % 100
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}
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/* Query operation */
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pub fn get(&self, key: i32) -> Option<&String> {
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let index = self.hash_func(key);
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self.buckets[index].as_ref().map(|pair| &pair.val)
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}
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/* Add operation */
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pub fn put(&mut self, key: i32, val: &str) {
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let index = self.hash_func(key);
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self.buckets[index] = Some(Pair {
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key,
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val: val.to_string(),
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});
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}
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/* Remove operation */
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pub fn remove(&mut self, key: i32) {
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let index = self.hash_func(key);
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// Set to None, representing removal
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self.buckets[index] = None;
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}
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/* Get all key-value pairs */
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pub fn entry_set(&self) -> Vec<&Pair> {
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self.buckets
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.iter()
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.filter_map(|pair| pair.as_ref())
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.collect()
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}
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/* Get all keys */
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pub fn key_set(&self) -> Vec<&i32> {
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self.buckets
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.iter()
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.filter_map(|pair| pair.as_ref().map(|pair| &pair.key))
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.collect()
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}
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/* Get all values */
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pub fn value_set(&self) -> Vec<&String> {
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self.buckets
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.iter()
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.filter_map(|pair| pair.as_ref().map(|pair| &pair.val))
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.collect()
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}
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/* Print hash table */
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pub fn print(&self) {
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for pair in self.entry_set() {
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println!("{} -> {}", pair.key, pair.val);
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}
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}
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}
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fn main() {
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/* Initialize hash table */
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let mut map = ArrayHashMap::new();
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/*Add operation */
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// Add key-value pair (key, value) to the hash table
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map.put(12836, "Ha");
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map.put(15937, "Luo");
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map.put(16750, "Suan");
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map.put(13276, "Fa");
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map.put(10583, "Ya");
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println!("\nAfter adding, the hash table is\nKey -> Value");
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map.print();
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/* Query operation */
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// Enter key to the hash table, get value
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let name = map.get(15937).unwrap();
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println!("\nInput student ID 15937, found name {}", name);
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/* Remove operation */
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// Remove key-value pair (key, value) from the hash table
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map.remove(10583);
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println!("\nAfter removing 10583, the hash table is\nKey -> Value");
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map.print();
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/* Traverse hash table */
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println!("\nTraverse key-value pairs Key->Value");
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for pair in map.entry_set() {
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println!("{} -> {}", pair.key, pair.val);
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}
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println!("\nIndividually traverse keys Key");
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for key in map.key_set() {
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println!("{}", key);
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}
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println!("\nIndividually traverse values Value");
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for val in map.value_set() {
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println!("{}", val);
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}
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}
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