src/bin/insert-delete-getrandom-o1.rs

bestgopher · bestgopher · commit 3161d719ca3d · 2021-08-15T22:19:21.000+08:00
diff --git a/src/bin/insert-delete-getrandom-o1.rs b/src/bin/insert-delete-getrandom-o1.rs
@@ -0,0 +1,52 @@
+fn main() {}
+
+struct Solution;
+
+/**
+ * Your RandomizedSet object will be instantiated and called as such:
+ * let obj = RandomizedSet::new();
+ * let ret_1: bool = obj.insert(val);
+ * let ret_2: bool = obj.remove(val);
+ * let ret_3: i32 = obj.get_random();
+ */
+struct RandomizedSet {
+    set: std::cell::RefCell<std::collections::HashSet<i32>>,
+}
+
+
+/**
+ * `&self` means the method takes an immutable reference.
+ * If you need a mutable reference, change it to `&mut self` instead.
+ */
+impl RandomizedSet {
+    /** Initialize your data structure here. */
+    fn new() -> Self {
+        Self {
+            set: std::cell::RefCell::new(std::collections::HashSet::default()),
+        }
+    }
+
+    /** Inserts a value to the set. Returns true if the set did not already contain the specified element. */
+    fn insert(&self, val: i32) -> bool {
+        self.set.borrow_mut().insert(val)
+    }
+
+    /** Removes a value from the set. Returns true if the set contained the specified element. */
+    fn remove(&self, val: i32) -> bool {
+        self.set.borrow_mut().remove(&val)
+    }
+
+    /** Get a random element from the set. */
+    fn get_random(&self) -> i32 {
+        use rand::Rng;
+        let mut rng = rand::thread_rng();
+        let s = rng.gen_range(0..self.set.borrow().len());
+        for (i, v) in self.set.borrow().iter().enumerate() {
+            if i == s {
+                return *v;
+            }
+        }
+
+        0
+    }
+}
