create 0706 in rust

rust/0706-design-hashmap.rs

@@ -0,0 +1,45 @@
+struct MyHashMap {
+ buckets: Vec<Vec<(i32,i32)>>,
+}
+
+// Prime number of buckets to reduce collisions
+const N_BUCKETS: usize = 1031;
+
+impl MyHashMap {
+
+ fn new() -> Self {
+ Self{ buckets: vec![vec![]; N_BUCKETS] }
+ }
+
+ fn hash(key: i32) -> usize {
+ key as usize % N_BUCKETS
+ }
+
+ fn find_entry(&mut self, key: i32) -> (&mut Vec<(i32, i32)>, Result<usize, usize>) {
+ let bucket = &mut self.buckets[Self::hash(key)];
+ let result = bucket.binary_search_by(|(k, v)| k.cmp(&key));
+ (bucket, result)
+ }
+
+ fn put(&mut self, key: i32, value: i32) {
+ match self.find_entry(key) {
+ (bucket, Ok(index)) => bucket[index] = (key, value),
+ (bucket, Err(index)) => bucket.insert(index, (key, value)),
+ }
+ }
+
+ fn get(&self, key: i32) -> i32 {
+ let bucket = &self.buckets[Self::hash(key)];
+ match bucket.binary_search_by(|(k, v)| k.cmp(&key)) {
+ Ok(index) => bucket[index].1,
+ Err(index) => -1,
+ }
+ }
+
+ fn remove(&mut self, key: i32) {
+ match self.find_entry(key) {
+ (bucket, Ok(index)) => { bucket.remove(index); },
+ _ => (),
+ }
+ }
+}