leetcode/src/problem/p155_min_stack.rs
2024-05-18 10:05:58 +08:00

70 lines
1.2 KiB
Rust

/**
* [155] Min Stack
*/
pub struct Solution {}
// submission codes start here
use std::{cmp::Reverse, collections::BinaryHeap};
struct MinStack {
heap : BinaryHeap<Reverse<i32>>,
stack: Vec<i32>
}
/**
* `&self` means the method takes an immutable reference.
* If you need a mutable reference, change it to `&mut self` instead.
*/
impl MinStack {
fn new() -> Self {
MinStack {
heap: BinaryHeap::new(),
stack: vec![]
}
}
fn push(&mut self, val: i32) {
self.heap.push(Reverse(val));
self.stack.push(val);
}
fn pop(&mut self) {
let n = self.stack.pop().unwrap_or(0);
if !self.stack.contains(&n) {
self.heap.retain(|i| i.0 != n);
}
}
fn top(&self) -> i32 {
*self.stack.last().unwrap_or(&0)
}
fn get_min(&self) -> i32 {
self.heap.peek().unwrap_or(&Reverse(0)).0
}
}
/**
* Your MinStack object will be instantiated and called as such:
* let obj = MinStack::new();
* obj.push(val);
* obj.pop();
* let ret_3: i32 = obj.top();
* let ret_4: i32 = obj.get_min();
*/
// submission codes end
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_155() {
}
}