20240303 Finished

src/problem/mod.rs

@@ -62,3 +62,4 @@ mod p2673_make_costs_of_paths_equal_in_a_binary_tree;
 mod p2581_count_number_of_possible_root_nodes;
 mod p2369_check_if_there_is_a_valid_partition_for_the_array;
 mod p2368_reachable_nodes_with_restrictions;
+mod p225_implement_stack_using_queues;

src/problem/p225_implement_stack_using_queues.rs

@@ -0,0 +1,77 @@
+/**
+ * [225] Implement Stack using Queues
+ */
+pub struct Solution {}
+
+
+// submission codes start here
+use std::collections::VecDeque;
+
+struct MyStack {
+    queue: VecDeque<i32>
+}
+
+
+/**
+ * `&self` means the method takes an immutable reference.
+ * If you need a mutable reference, change it to `&mut self` instead.
+ */
+impl MyStack {
+
+    fn new() -> Self {
+        return MyStack {
+            queue: VecDeque::new()
+        }
+    }
+    
+    fn push(&mut self, x: i32) {
+        let mut new_queue = VecDeque::with_capacity(self.queue.capacity() + 1);
+        new_queue.push_back(x);
+
+        for i in &self.queue {
+            new_queue.push_back(*i);
+        }
+
+        self.queue = new_queue;
+    }
+    
+    fn pop(&mut self) -> i32 {
+        self.queue.pop_front().unwrap()
+    }
+    
+    fn top(&self) -> i32 {
+        *self.queue.front().unwrap()
+    }
+    
+    fn empty(&self) -> bool {
+        self.queue.is_empty()
+    }
+}
+
+/**
+ * Your MyStack object will be instantiated and called as such:
+ * let obj = MyStack::new();
+ * obj.push(x);
+ * let ret_2: i32 = obj.pop();
+ * let ret_3: i32 = obj.top();
+ * let ret_4: bool = obj.empty();
+ */
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_225() {
+        let mut stack = MyStack::new();
+
+        stack.push(1);
+        stack.push(2);
+
+        assert_eq!(2, stack.top());
+        assert_eq!(2, stack.pop());
+        assert!(!stack.empty());
+    }
+}