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use std::fs;
fn solve_part1(rows: &Vec<Vec<usize>>) -> usize {
let mut num_valid: usize = 0;
for row in rows {
let mut sides = row.clone();
sides.sort();
if sides[0] + sides[1] > sides[2] {
num_valid += 1;
}
}
num_valid
}
fn solve_part2(rows: &Vec<Vec<usize>>) -> usize {
let mut num_valid: usize = 0;
// For each 3 consecutive rows of data
for i in 0..(rows.len() / 3) {
// For each of the 3 numbers per row
for j in 0..3 {
let mut sides = Vec::new();
// For each row in this group of 3 rows
for k in 0..3 {
sides.push(rows[3 * i + k][j]);
}
sides.sort();
if sides[0] + sides[1] > sides[2] {
num_valid += 1;
}
}
}
num_valid
}
fn main() {
// Read and parse triangle data from input text file
let input = fs::read_to_string("input.txt").unwrap();
let lines: Vec<&str> = input.lines().collect();
let words: Vec<Vec<&str>> = lines
.into_iter()
.map(|l| l.split_ascii_whitespace().collect())
.collect();
let rows: Vec<Vec<usize>> = words
.into_iter()
.map(|w123| w123
.into_iter()
.map(|s| s.parse().unwrap())
.collect())
.collect();
// Part 1 gives 993 for me
println!("Part 1 solution: {}", solve_part1(&rows));
// Part 2 gives 1849 for me
println!("Part 2 solution: {}", solve_part2(&rows));
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn part1_example1() {
let rows = vec![
vec![5, 10, 25],
vec![3, 4, 5],
];
assert_eq!(solve_part1(&rows), 1);
}
#[test]
fn part2_example1() {
let rows = vec![
vec![101, 301, 501],
vec![102, 302, 502],
vec![103, 303, 503],
vec![201, 401, 601],
vec![202, 402, 602],
vec![203, 403, 603],
];
assert_eq!(solve_part2(&rows), 6);
}
}
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