added day 19

src/day19/1.rs

@@ -0,0 +1,61 @@
+#![feature(test)]
+extern crate test;
+
+use fxhash::FxHashSet;
+
+const INPUTS: [&str; 2] = [
+    "r, wr, b, g, bwu, rb, gb, br
+
+brwrr
+bggr
+gbbr
+rrbgbr
+ubwu
+bwurrg
+brgr
+bbrgwb",
+    include_str!("./input.txt"),
+];
+
+pub fn run(input: &str) -> i64 {
+    let (towels, to_make) = input.split_once("\n\n").unwrap();
+    let towels = towels.split(", ").map(|x| x.bytes().collect::<Vec<u8>>()).collect::<FxHashSet<Vec<u8>>>();
+    let to_make = to_make.lines().map(|x| x.bytes().collect::<Vec<u8>>());
+
+    let mut count = 0;
+    for pattern in to_make {
+        count += test(&towels, &pattern) as i64;
+    }
+    count
+}
+
+fn test(towels: &FxHashSet<Vec<u8>>, pattern: &[u8]) -> bool {
+    let n = pattern.len();
+    let mut dp = vec![false; n + 1];
+    dp[0] = true;
+
+    for i in 1..n+1 {
+        for j in 0..i {
+            if dp[j] && towels.contains(&pattern[j..i]) {
+                dp[i] = true;
+                break;
+            }
+        }
+    }
+
+    dp[n]
+}
+
+fn main() {
+    for input in INPUTS.iter() {
+        println!("answer = {}", run(input));
+    }
+}
+
+#[bench]
+fn part1(b: &mut test::Bencher) {
+    b.iter(|| {
+        let v = run(INPUTS[1]);
+        test::black_box(v);
+    });
+}

src/day19/2.rs

@@ -0,0 +1,61 @@
+#![feature(test)]
+extern crate test;
+
+use fxhash::FxHashSet;
+
+const INPUTS: [&str; 2] = [
+    "r, wr, b, g, bwu, rb, gb, br
+
+brwrr
+bggr
+gbbr
+rrbgbr
+ubwu
+bwurrg
+brgr
+bbrgwb",
+    include_str!("./input.txt"),
+];
+
+pub fn run(input: &str) -> i64 {
+    let (towels, to_make) = input.split_once("\n\n").unwrap();
+    let towels = towels.split(", ").map(|x| x.bytes().collect::<Vec<u8>>()).collect::<FxHashSet<Vec<u8>>>();
+    let to_make = to_make.lines().map(|x| x.bytes().collect::<Vec<u8>>());
+
+    let mut count = 0;
+    for pattern in to_make {
+        let sum = test(&towels, &pattern);
+        count += sum;
+    }
+    count
+}
+
+fn test(towels: &FxHashSet<Vec<u8>>, pattern: &[u8]) -> i64 {
+    let n = pattern.len();
+    let mut dp = vec![0; n + 1];
+    dp[0] = 1; // only 1 way to make an empty string
+
+    for i in 1..n+1 {
+        for j in 0..i {
+            if towels.contains(&pattern[j..i]) {
+                dp[i] += dp[j];
+            }
+        }
+    }
+
+    dp[n]
+}
+
+fn main() {
+    for input in INPUTS.iter() {
+        println!("answer = {}", run(input));
+    }
+}
+
+#[bench]
+fn part1(b: &mut test::Bencher) {
+    b.iter(|| {
+        let v = run(INPUTS[1]);
+        test::black_box(v);
+    });
+}