use std::cmp;

pub fn max_satisfaction(mut satisfaction: Vec<i32>) -> i32 {
    // First we want to sort the dishes, because the maximum like-time will come
    // when the last dishes are highest in number - then we just need to work out which ones to cull
    // there is one case that can probably be optimised: all negative (cook nothing)
    // but it might be easier to just build that into the starting logic
    satisfaction.sort_by(|a, b| b.cmp(a));
    let mut max = 0;
    let mut sum = 0; // sum will count how much will be added by multiplying the end of the arr
    // Now loop backwards over the array seeing if it makes things better to add dishes
    // Note: The array has been reversed, so it's actually going forwards, trippy right?
    for dish in satisfaction {
        let total = max + dish + sum; // This is the total if this dish was added
        if total > max {
            sum = sum + dish;
            max = total;
        } else {
            return max; // we can't do better, stop here
        }
    }
    return cmp::max(0, max);
}

pub fn main() {
    println!("Expected: 20");
    println!("Got: {}", max_satisfaction(vec![4, 3, 2]));
}