leetcode/lcci/03.04.Implement Queue using.../Solution.rs

42 lines
785 B
Rust

use std::collections::VecDeque;
struct MyQueue {
stk1: Vec<i32>,
stk2: Vec<i32>,
}
impl MyQueue {
fn new() -> Self {
MyQueue {
stk1: Vec::new(),
stk2: Vec::new(),
}
}
fn push(&mut self, x: i32) {
self.stk1.push(x);
}
fn pop(&mut self) -> i32 {
self.move_elements();
self.stk2.pop().unwrap()
}
fn peek(&mut self) -> i32 {
self.move_elements();
*self.stk2.last().unwrap()
}
fn empty(&self) -> bool {
self.stk1.is_empty() && self.stk2.is_empty()
}
fn move_elements(&mut self) {
if self.stk2.is_empty() {
while let Some(element) = self.stk1.pop() {
self.stk2.push(element);
}
}
}
}