How to Use BinaryHeap (Priority Queue) in Rust

Use std::collections::BinaryHeap to efficiently manage a priority queue that automatically keeps the highest priority element accessible in constant time.

Use std::collections::BinaryHeap to manage a priority queue where the largest element is always at the top.

use std::collections::BinaryHeap;

fn main() {
    let mut heap = BinaryHeap::new();
    heap.push(3);
    heap.push(1);
    heap.push(4);
    
    // Pop returns the largest element first (4, then 3, then 1)
    while let Some(val) = heap.pop() {
        println!("{}", val);
    }
}

Note: BinaryHeap is a max-heap by default. To create a min-heap, wrap your items in a custom struct implementing Ord that reverses the comparison logic.

A BinaryHeap is a data structure that keeps your most important item at the very top, ready to be grabbed instantly. Think of it like a line at a hospital triage where the most critical patient is always seen first, regardless of when they arrived. You use it when you need to constantly access the highest or lowest priority item in a large, changing list without sorting the whole list every time.