use std::{collections::HashSet, fs};

fn main() {
    let file = fs::read_to_string("./input.txt").unwrap();
    let mut rows = Vec::new();

    for line in file.lines() {
        let vals = line
            .split_whitespace()
            .map(|x| x.parse::<i32>().unwrap())
            .collect::<Vec<i32>>();

        rows.push(vals);
    }

    println!("Solution 1: {}", puzzle1(rows.clone()));
    println!("Solution 2: {}", puzzle2(rows));
}

fn puzzle1(rows: Vec<Vec<i32>>) -> i32 {
    let mut counter = 0;
    for r in rows {
        if is_safe(&r) {
            counter += 1;
        }
    }
    counter
}

fn puzzle2(rows: Vec<Vec<i32>>) -> i32 {
    let mut counter = 0;
    for r in rows {
        if is_safe(&r) {
            counter += 1;
            continue;
        }

        for i in 0..r.len() {
            let mut modrow = r.clone();
            modrow.remove(i);
            if is_safe(&modrow) {
                counter += 1;
                break;
            }
        }
    }
    counter
}

fn is_safe(row: &[i32]) -> bool {
    let mut safeslopes: HashSet<i32> = HashSet::from_iter(vec![1, 2, 3]);
    let mut safenegslopes: HashSet<i32> = HashSet::from_iter(vec![-1, -2, -3]);

    for i in 1..row.len() {
        let diff = row[i] - row[i - 1];
        safeslopes.insert(diff);
        safenegslopes.insert(diff);
    }

    safeslopes.len() == 3 || safenegslopes.len() == 3
}