Method pop

155. Min Stack/src/main.rs:31–37

(&mut self)

    }
    
    fn pop(&mut self) {
        if let Some(x) = self.s.pop() {
            if self.ms.last() == Some(&x) {
                self.ms.pop();
            }
        }
    }
    
    fn top(&self) -> i32 {
        self.s.last().copied().unwrap()