Day 5 - Part 2

Signed-off-by: Anthony Oteri <anthony.oteri@gmail.com>

day-05/Cargo.toml

@@ -6,3 +6,4 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+indicatif = { version = "0.17.7", features = ["rayon"] }

day-05/src/main.rs

@@ -1,15 +1,17 @@
+use indicatif::ProgressIterator;
 use std::collections::BTreeMap;
+use std::collections::BinaryHeap;
 
-const SOIL: &'static str = "seed-to-soil";
+const SOIL: &str = "seed-to-soil";
-const FERT: &'static str = "soil-to-fertilizer";
+const FERT: &str = "soil-to-fertilizer";
-const WATER: &'static str = "fertilizer-to-water";
+const WATER: &str = "fertilizer-to-water";
-const LIGHT: &'static str = "water-to-light";
+const LIGHT: &str = "water-to-light";
-const TEMP: &'static str = "light-to-temperature";
+const TEMP: &str = "light-to-temperature";
-const HUMIDITY: &'static str = "temperature-to-humidity";
+const HUMIDITY: &str = "temperature-to-humidity";
-const LOC: &'static str = "humidity-to-location";
+const LOC: &str = "humidity-to-location";
 
 fn extract_seeds(input: &str) -> Vec<usize> {
-    let line = input.lines().nth(0).unwrap();
+    let line = input.lines().next().unwrap();
     let (_, values) = line.split_once(':').unwrap();
     values
         .split_whitespace()
@@ -30,8 +32,8 @@ fn extract_map_lines(input: &str, key: &'static str) -> Vec<String> {
     lines
 }
 
-fn lookup(input: &str, source: usize, map: &'static str) -> usize {
+fn lookup(maps: &BTreeMap<&'static str, Vec<String>>, source: usize, map: &'static str) -> usize {
-    let map_lines = extract_map_lines(input, map);
+    let map_lines = maps.get(map).unwrap();
 
     for line in map_lines {
         let values: Vec<usize> = line
@@ -52,39 +54,118 @@ fn lookup(input: &str, source: usize, map: &'static str) -> usize {
     source
 }
 
-fn lookup_location(input: &str, seed: usize) -> usize {
+fn rev_lookup(maps: &BTreeMap<&'static str, Vec<String>>, dest: usize, map: &'static str) -> usize {
-    dbg!(&seed);
+    let map_lines = maps.get(map).unwrap();
-    let soil = lookup(input, seed, SOIL);
-    dbg!(&soil);
 
-    let fert = lookup(input, soil, FERT);
+    for line in map_lines {
-    dbg!(&fert);
+        let values: Vec<usize> = line
-    let water = lookup(input, fert, WATER);
+            .split_whitespace()
-    dbg!(&water);
+            .map(|s| s.parse::<usize>().unwrap())
-    let light = lookup(input, water, LIGHT);
+            .collect();
-    dbg!(&light);
-    let temp = lookup(input, light, TEMP);
-    dbg!(&temp);
-    let humidity = lookup(input, temp, HUMIDITY);
-    dbg!(&humidity);
-    let loc = lookup(input, humidity, LOC);
-    dbg!(&loc);
 
-    loc
+        let dest_range_start = values[0];
+        let source_range_start = values[1];
+        let range_length = values[2];
+
+        let dest_range_end = dest_range_start + range_length;
+        if dest >= dest_range_start && dest < dest_range_end {
+            return source_range_start + (dest - dest_range_start);
+        }
+    }
+
+    dest
+}
+
+fn lookup_location(maps: &BTreeMap<&'static str, Vec<String>>, seed: usize) -> usize {
+    let soil = lookup(maps, seed, SOIL);
+
+    let fert = lookup(maps, soil, FERT);
+    let water = lookup(maps, fert, WATER);
+    let light = lookup(maps, water, LIGHT);
+    let temp = lookup(maps, light, TEMP);
+    let humidity = lookup(maps, temp, HUMIDITY);
+    
+
+    lookup(maps, humidity, LOC)
+}
+
+fn rev_lookup_location(maps: &BTreeMap<&'static str, Vec<String>>, loc: usize) -> usize {
+    let humidity = rev_lookup(maps, loc, LOC);
+    let temp = rev_lookup(maps, humidity, HUMIDITY);
+    let light = rev_lookup(maps, temp, TEMP);
+    let water = rev_lookup(maps, light, LIGHT);
+    let fert = rev_lookup(maps, water, WATER);
+    let soil = rev_lookup(maps, fert, FERT);
+    
+
+    rev_lookup(maps, soil, SOIL)
+}
+
+fn extract_maps(input: &str) -> BTreeMap<&'static str, Vec<String>> {
+    let mut maps = BTreeMap::new();
+    maps.insert(SOIL, extract_map_lines(input, SOIL));
+    maps.insert(FERT, extract_map_lines(input, FERT));
+    maps.insert(WATER, extract_map_lines(input, WATER));
+    maps.insert(LIGHT, extract_map_lines(input, LIGHT));
+    maps.insert(TEMP, extract_map_lines(input, TEMP));
+    maps.insert(HUMIDITY, extract_map_lines(input, HUMIDITY));
+    maps.insert(LOC, extract_map_lines(input, LOC));
+    maps
 }
 
 fn part_1(input: &str) -> u32 {
+    let maps = extract_maps(input);
     let seeds = extract_seeds(input);
     let mut locs = Vec::new();
     for seed in seeds {
-        locs.push(lookup_location(input, seed));
+        locs.push(lookup_location(&maps, seed));
     }
-    locs.iter().min().unwrap().clone() as u32
+    *locs.iter().min().unwrap() as u32
+}
+
+fn part_2(input: &str) -> usize {
+    let maps = extract_maps(input);
+    let seed_pairs = extract_seeds(input);
+
+    let mut ranges = Vec::new();
+    for chunk in seed_pairs.chunks(2) {
+        let start = chunk[0];
+        let size = chunk[1];
+        ranges.push(start..start + size);
+    }
+
+    let mut h2l = maps.get(LOC).unwrap().iter().collect::<BinaryHeap<_>>();
+
+    let line = h2l.pop().unwrap();
+    let values: Vec<usize> = line
+        .split_whitespace()
+        .map(|s| s.parse::<usize>().unwrap())
+        .collect();
+
+    let dest_range_start = values[0];
+    let range_length = values[2];
+
+    let rng = 0..dest_range_start + range_length;
+
+    rng.into_iter()
+        .progress()
+        .find(|loc| {
+            let seed = rev_lookup_location(&maps, *loc);
+            for range in &ranges {
+                if range.contains(&seed) {
+                    return true;
+                }
+            }
+            false
+        })
+        .unwrap()
+    //    0
 }
 
 fn main() {
     let input = include_str!("../input.txt");
     println!("Part 1: {}", part_1(input));
+    println!("Part 2: {}", part_2(input));
 }
 
 #[cfg(test)]
@@ -108,20 +189,33 @@ mod tests {
     #[test]
     fn test_lookup_location() {
         let input = include_str!("../test-input.txt");
+        let maps = extract_maps(input);
 
-        assert_eq!(lookup_location(input, 79), 82);
+        assert_eq!(lookup_location(&maps, 79), 82);
-        assert_eq!(lookup_location(input, 14), 43);
+        assert_eq!(lookup_location(&maps, 14), 43);
-        assert_eq!(lookup_location(input, 55), 86);
+        assert_eq!(lookup_location(&maps, 55), 86);
-        assert_eq!(lookup_location(input, 13), 35);
+        assert_eq!(lookup_location(&maps, 13), 35);
+    }
+
+    #[test]
+    fn test_reverse_lookup() {
+        let input = include_str!("../test-input.txt");
+        let maps = extract_maps(input);
+
+        assert_eq!(rev_lookup_location(&maps, 82), 79);
+        assert_eq!(rev_lookup_location(&maps, 43), 14);
+        assert_eq!(rev_lookup_location(&maps, 86), 55);
+        assert_eq!(rev_lookup_location(&maps, 35), 13);
     }
 
     #[test]
     fn test_lookup() {
         let input = include_str!("../test-input.txt");
-        assert_eq!(lookup(input, 79, SOIL), 81);
+        let maps = extract_maps(input);
-        assert_eq!(lookup(input, 14, SOIL), 14);
+        assert_eq!(lookup(&maps, 79, SOIL), 81);
-        assert_eq!(lookup(input, 55, SOIL), 57);
+        assert_eq!(lookup(&maps, 14, SOIL), 14);
-        assert_eq!(lookup(input, 13, SOIL), 13);
+        assert_eq!(lookup(&maps, 55, SOIL), 57);
+        assert_eq!(lookup(&maps, 13, SOIL), 13);
     }
 
     #[test]
@@ -129,4 +223,10 @@ mod tests {
         let input = include_str!("../test-input.txt");
         assert_eq!(part_1(input), 35);
     }
+
+    #[test]
+    fn test_part_2() {
+        let input = include_str!("../test-input.txt");
+        assert_eq!(part_2(input), 46);
+    }
 }