My attempts to solve puzzles of Advent of Code
feat: day 6
+81
-1
+1
-1
src/main.rs
+1
-1
src/main.rs
+76
src/solutions/year_2023/day6.rs
+76
src/solutions/year_2023/day6.rs
···
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use std::ops::Sub;
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use aoc_lib::{create_solution, Input, Solver};
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pub struct Day6 {}
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fn solve_x(x: usize, y: usize) -> Vec<usize> {
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(1..x).fold(vec![], |mut acc, a| {
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if a * (x - a) > y {
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acc.push(a)
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}
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acc
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})
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}
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fn solve_xs(inp: Vec<(usize, usize)>) -> Vec<usize> {
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inp.into_iter().map(|(x, y)| solve_x(x, y).len()).collect()
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}
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fn solve_eq(x: usize, y: usize) -> usize {
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let s = ((x as f64).powf(2.0) - (4.0 * y as f64)).abs().sqrt();
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let root1: f64 = (x as f64 - s) / 2.0;
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let root2: f64 = (x as f64 + s) / 2.0;
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if root1.floor() == root1 {
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(root2 - (root1 + 1.0)) as usize + 1
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} else if root2.ceil() == root2 {
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((root2 - 1.0) - root1) as usize + 1
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} else {
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(root2 - root1) as usize + 1
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}
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}
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fn solve_eqs(inp: Vec<(usize, usize)>) -> usize {
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inp.into_iter().map(|(x, y)| solve_eq(x, y)).product()
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}
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create_solution!(
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out_1 => usize;
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out_2 => usize;
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year => 2023;
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day => 6;
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sol_1 => |input: Input| {
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let inp = vec![
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(40, 219),
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(81, 1012),
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(77, 1365),
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(72, 1089),
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];
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// Some(solve_xs(inp).iter().product())
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Some(solve_eqs(inp))
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};
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sol_2 => |input: Input| {
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let inp = vec![
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(40817772, 219101213651089),
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];
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// Some(solve_xs(inp).iter().product())
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Some(solve_eqs(inp))
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};
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);
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn test_solve_xs() {
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let inp = vec![
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(7, 9),
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(15, 40),
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(30, 200),
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];
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let act: usize = solve_xs(inp).iter().product();
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assert_eq!(act, 288)
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}
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}