create 0706 in rust

Author: Mohammed785

Diff for: 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); },
+            _ => (),
+        }
+    }
+}