feat: 706_design_hashmap

706_design_hashmap/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "design_hashmap"
+version = "0.1.0"

706_design_hashmap/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "design_hashmap"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

706_design_hashmap/src/lib.rs

@@ -0,0 +1,57 @@
+use std::hash::{DefaultHasher, Hash, Hasher};
+
+pub struct MyHashMap {
+    capacity: usize,
+    buckets: Vec<Vec<(i32, i32)>>,
+}
+
+impl MyHashMap {
+    pub fn new() -> Self {
+        let capacity = 8192;
+        Self {
+            capacity: capacity,
+            buckets: vec![Vec::new(); capacity],
+        }
+    }
+
+    pub fn put(&mut self, key: i32, value: i32) {
+        let index = self.get_bucket_index(key);
+        let list = &mut self.buckets[index];
+
+        let node = list.iter_mut().find(|node| node.0 == key);
+        match node {
+            Some(node) => {
+                node.1 = value;
+            }
+            None => {
+                list.push((key, value));
+            }
+        }
+    }
+
+    pub fn get(&mut self, key: i32) -> i32 {
+        let index = self.get_bucket_index(key);
+        let list = &self.buckets[index];
+
+        let node = list.iter().find(|node| node.0 == key);
+        match node {
+            Some(node) => node.1,
+            None => -1,
+        }
+    }
+
+    pub fn remove(&mut self, key: i32) {
+        let index = self.get_bucket_index(key);
+        let list = &mut self.buckets[index];
+
+        if let Some(index_to_remove) = list.iter().position(|node| node.0 == key) {
+            list.remove(index_to_remove);
+        }
+    }
+
+    fn get_bucket_index(&mut self, key: i32) -> usize {
+        let mut hasher = DefaultHasher::new();
+        key.hash(&mut hasher);
+        hasher.finish() as usize & (self.capacity - 1)
+    }
+}