Discussion on: Daily Coding Puzzles - Nov 11th - Nov 16th

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Replies for: Thursday - Queue from two stacks (Hacker Rank Medium) Complete the put, pop, and peek methods in the editor below. They must perform the actions ...

Rust Solution:

struct MyQueue {
    stack1: Vec<i32>,
    stack2: Vec<i32>,
}

impl MyQueue {
    pub fn new() -> Self {
        MyQueue {
            stack1: vec![],
            stack2: vec![],
        }
    }

    pub fn push(&mut self, x: i32) {
        self.stack1.push(x);
    }

    pub fn pop(&mut self) {
        if self.stack2.is_empty() {
            while !self.stack1.is_empty() {
                self.stack2.push(self.stack1.pop().unwrap());
            }
        }
        self.stack2.pop();
    }

    pub fn peek(&mut self) -> i32 {
        if self.stack2.is_empty() {
            while !self.stack1.is_empty() {
                self.stack2.push(self.stack1.pop().unwrap());
            }
        }
        *self.stack2.last().unwrap()
    }
}