day 19 pt1

data/examples/19.txt

@@ -0,0 +1,10 @@
+r, wr, b, g, bwu, rb, gb, br
+
+brwrr
+bggr
+gbbr
+rrbgbr
+ubwu
+bwurrg
+brgr
+bbrgwb

src/bin/19.rs

@@ -0,0 +1,140 @@
+use itertools::Itertools;
+use std::io::{stdout, Write};
+
+advent_of_code::solution!(19);
+
+#[derive(Debug, PartialEq)]
+#[repr(u8)]
+enum Color {
+    White,
+    Blue,
+    Black,
+    Red,
+    Green
+}
+
+pub fn part_one(input: &str) -> Option<u32> {
+    let mut lines = input.lines();
+    let patterns = lines.next().unwrap().split(", ").map(|p| p.chars().map(map_color).collect_vec()).collect_vec();
+    let patterns_slice = patterns.iter().map(Vec::as_slice).collect_vec();
+    let designs = lines.by_ref().skip(1).map(|d| d.chars().map(map_color).collect_vec()).collect_vec();
+
+    let possible_designs = designs.iter().filter(|design| {
+        is_design_possible(design, &patterns_slice)
+    });
+
+
+
+    Some(possible_designs.collect_vec().len() as u32)
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    let mut lines = input.lines();
+    let patterns = lines.next().unwrap().split(", ").map(|p| p.chars().map(map_color).collect_vec()).collect_vec();
+    let patterns_slice = patterns.iter().map(Vec::as_slice).collect_vec();
+    let designs = lines.by_ref().skip(1).map(|d| d.chars().map(map_color).collect_vec()).collect_vec();
+
+    let possible_designs: usize = designs.iter().map(|design| {
+        print!(".");
+        let _ = stdout().flush();
+        all_possible_designs(design, &patterns_slice)
+    }).sum();
+
+    Some(possible_designs as u32)
+}
+
+fn map_color(c: char) -> Color {
+    match c {
+        'w' => Color::White,
+        'u' => Color::Blue,
+        'b' => Color::Black,
+        'r' => Color::Red,
+        'g' => Color::Green,
+        _ => panic!()
+    }
+}
+
+fn is_design_possible(design: &[Color], patterns: &[&[Color]]) -> bool {
+    // if the remaining design exists as a pattern, use that
+    if patterns.contains(&design) { return true; }
+
+    // otherwise find all the patterns that satisfy the next step of the design and check if that is a workable design
+    patterns.iter().any(|pattern| {
+        // eg design = abcd, patterns = [bbbbb, a, ab,cd] will match 'a' and 'ab'
+        if design.len() > pattern.len() && design[0..pattern.len()] == **pattern {
+            is_design_possible(&design[pattern.len()..], patterns)
+        } else {
+            false
+        }
+    })
+}
+
+fn all_possible_designs(design: &[Color], patterns: &[&[Color]]) -> usize {
+    println!("Checking {} stripe design against {} patterns", design.len(), patterns.len());
+    let _ = stdout().flush();
+    patterns.iter().map(|pattern| {
+        if design == *pattern {
+            return 1
+        } else if design.len() > pattern.len() && design[0..pattern.len()] == **pattern {
+            all_possible_designs(&design[pattern.len()..], patterns)
+        } else {
+            0
+        }
+    }).sum()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_all_possible_designs() {
+        let patterns = "r, wr, b, g, bwu, rb, gb, br".split(", ").map(|p| p.chars().map(map_color).collect_vec()).collect_vec();
+        let patterns_slice = patterns.iter().map(Vec::as_slice).collect_vec();
+
+        let design = "brwrr".chars().map(map_color).collect_vec();
+        assert_eq!(2, all_possible_designs(&design, &patterns_slice));
+
+        let design = "bggr".chars().map(map_color).collect_vec();
+        assert_eq!(1, all_possible_designs(&design, &patterns_slice));
+
+        let design = "gbbr".chars().map(map_color).collect_vec();
+        assert_eq!(4, all_possible_designs(&design, &patterns_slice));
+
+        let design = "rrbgbr".chars().map(map_color).collect_vec();
+        assert_eq!(6, all_possible_designs(&design, &patterns_slice));
+
+        let design = "bwurrg".chars().map(map_color).collect_vec();
+        assert_eq!(1, all_possible_designs(&design, &patterns_slice));
+
+        let design = "brgr".chars().map(map_color).collect_vec();
+        assert_eq!(2, all_possible_designs(&design, &patterns_slice));
+
+        let design = "ubwu".chars().map(map_color).collect_vec();
+        assert_eq!(0, all_possible_designs(&design, &patterns_slice));
+
+        let design = "bbrgwb".chars().map(map_color).collect_vec();
+        assert_eq!(0, all_possible_designs(&design, &patterns_slice));
+
+        // let patterns = "wubu, brr, uru, uw, gug, rgrur, ub, rrwg, wrw, uugg, wwb, gwrg, rgb, bbrbgw, guwb, rub, wgww, wgu, bwbu, bgubwb, gbuu, buwr, uub, wubgr, uwugbwb, gwwbbwrr, rbgbgr, gbuuww, bur, gubgbr, wgug, rrb, wbrugwrb, brb, gbu, rrwrbgrr, uburgr, bbrgrwg, rbbb, gbr, grgug, rr, wrbw, uugbgb, bbg, br, rubbbu, bbggubb, brwwr, rgwbrr, ubr, wgugg, grrburw, r, uuwrwug, gguw, ww, bbrb, bguw, uurr, bru, ru, bwubwrb, wur, wrbgru, bbug, gbbrw, rwbu, wrwrr, bgu, wrgbur, ubugg, wb, rguw, ubbrgbw, buwurgb, wrwruuu, rgwwu, wwrbw, uwwwubb, wg, wrgwrwur, gwg, wbw, wgrg, ruurruu, uwu, bwwbuuug, rbr, urgbg, gugu, gwgwbgur, gbg, gbwu, uur, ggwbb, grub, gwrrw, uuu, rwr, urwbu, uwwbrwgg, gbb, guwg, urguu, urwgug, grwuwu, rwb, rbwwbg, grbuwu, bwbbbb, rbgr, rwrrur, gur, rwruwg, uuwrw, wbb, uug, rrbr, wrbbb, ggwgg, wrrur, bub, ug, guubgw, gwubb, wub, rruw, uruwwww, rrugwb, urbu, wbbu, bggr, urgr, brww, bwg, rggwgg, urr, bbbgwbbw, bwrgw, ugb, gwr, uwugwgu, bbgrubb, wbr, brg, ggg, ububww, grw, grr, wrb, gbuubg, gbuuu, b, ubgw, gurrurg, urwwr, bggug, rrg, guwbwrw, urw, bwrurg, rubww, bb, bubur, bgrwu, bwb, uwr, bwgw, g, bwrbwgbb, bgwguw, guugg, wuggrru, ugbg, wuwgrrw, wrbrg, gb, u, gwgg, gbwrgbw, rgw, gwuwwg, ubgu, rgu, ggb, brurgw, rbrbgwr, guuu, bwwu, bug, bbrggg, bwuw, wbuwwbg, uburbgu, gub, www, rwu, wrgbwg, bwggrruw, ubgww, gbw, wwbrw, wrg, brw, brbg, wwuggg, uuubgr, bgru, bbb, wgr, wurrwubr, rur, rgugwbru, bbu, wbuw, rubuubgr, urug, uubr, bw, buu, rbw, ggwb, rrr, gwrbu, gu, gw, rwub, wrwug, uubg, rrbgr, bbbwr, wurggw, wgg, urbg, rrwuu, bwgb, ruw, gwrw, ggub, gwwrrb, bwgbw, rrw, gwb, rwbbb, rwwu, gggg, gbgugggw, brrgww, rgbbw, wgrguw, wrr, uwuw, bwbbgbgr, grb, buurbbrb, wgb, ugburb, ururw, ggrgbgw, rgr, gg, wggwb, bwrgu, wgw, wru, brwbu, wbrrg, gugr, uggw, bg, gubrguu, ubu, bww, rrbwrrwb, bgrbwww, bbw, bwrwrr, uuuug, bwrwb, bwggr, rggbw, bbgg, rw, ggbb, ggugwu, ggu, ruuuggu, ggw, bgwwb, rrggww, gurwgrg, rrruu, ubg, rrgw, wggu, ruu, bgwru, wrrgw, buww, ubb, buwgu, bbgr, uggb, rbb, bubg, grg, bwr, bwbwwb, ugubgb, rrwub, rgbr, wbbug, ruwr, ubgrgg, bbrgw, rwgwb, buwrw, bbwrw, rwgr, wwrwgr, urgrrw, brrbbug, bwu, wuw, rgg, gww, bbrwrb, wruur, bbubu, bbbb, bwbrb, guu, wuggw, wwuw, wbu, rrrg, bgr, wwbbgru, rgubuugu, rgrr, bbuurr, ruur, brgwr, bwgwb, rgrww, ugw, wrwr, guuw, rrgr, wbgb, wug, wbg, rggb, uww, rug, wrub, rguwb, wbrgr, brbwbgu, wruw, rb, gwuug, ubru, gbbbrbg, rbg, ubgb, burg, bbwbrwbu, uuww, wgbg, wrgrrr, gru, wr, rgwr, rww, uruwbrru, gwgu, uwb, wbwrgr, uu, ur, gurrrg, ugrguu, gwub, gwgw, bbr, ugg, wwbg, wwr, rwubbw, urg, gubr, uwbwr, buw, bgwgubu, wwu, wurgbw, wbrwb, grwub, urb, rubgu, rwwrrrr, rg, brbb, bgb, uwg, ugwbbbg, grrwwbb, gwrrggr, rubb, wbrguw, uwurbg, grrgb, ubw, wuwuw, rbbuwg, rwg, urbuub, gwu, bgg, wbug, wgwbb, uggwugg, bu, ugu, rguu, wgrbgw, brrggw, grrg, gbww, wwubu, gbubrb, bgw, uurgw, wwbu, wwg, ggbr, gbbrb, buurr, ugr, rrbrggu, rru, ggur, gbggwub, wrrbbgw, ruuguw"
+        //     .split(", ").map(|p| p.chars().map(map_color).collect_vec()).collect_vec();
+        // let patterns_slice = patterns.iter().map(Vec::as_slice).collect_vec();
+        // let design = "wguurwubgburbugwwuwrwwggrggubwrbwurrrrgbrbuggugurg".chars().map(map_color).collect_vec();
+
+        // assert_eq!(0, all_possible_designs(&design, &patterns_slice));
+
+    }
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(6));
+    }
+
+    #[test]
+    #[ignore]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(16));
+    }
+}