Added day 10

inputs/day10.txt

@@ -0,0 +1,108 @@
+115
+134
+121
+184
+78
+84
+77
+159
+133
+90
+71
+185
+152
+165
+39
+64
+85
+50
+20
+75
+2
+120
+137
+164
+101
+56
+153
+63
+70
+10
+72
+37
+86
+27
+166
+186
+154
+131
+1
+122
+95
+14
+119
+3
+99
+172
+111
+142
+26
+82
+8
+31
+53
+28
+139
+110
+138
+175
+108
+145
+58
+76
+7
+23
+83
+49
+132
+57
+40
+48
+102
+11
+105
+146
+149
+66
+38
+155
+109
+128
+181
+43
+44
+94
+4
+169
+89
+96
+60
+69
+9
+163
+116
+45
+59
+15
+178
+34
+114
+17
+16
+79
+91
+100
+162
+125
+156
+65

inputs/test.txt

@@ -1,3 +1,31 @@
-BFFFBBFRRR
-FFFBBBFRRR
-BBFFBBFRLL
+28
+33
+18
+42
+31
+14
+46
+20
+48
+47
+24
+23
+49
+45
+19
+38
+39
+11
+1
+32
+25
+35
+8
+17
+7
+9
+4
+2
+34
+10
+3

src/bin/day10.rs

@@ -0,0 +1,66 @@
+use itertools::Itertools;
+use std::collections::HashMap;
+use std::error::Error;
+use std::fs::File;
+use std::io::{self, BufRead};
+use std::vec::Vec;
+
+fn enumerate_chains(curr_jolts: u32, rest: &[u32], cache: &mut HashMap<(u32, u32), u64>) -> u64 {
+    if rest.len() == 0 {
+        println!("Finished path");
+        1
+    } else if rest[0] - curr_jolts > 3 {
+        println!("Termindated chain at {}", curr_jolts);
+        0
+    } else {
+        let jolts = rest[0];
+
+        if cache.contains_key(&(curr_jolts, jolts)) {
+            println!("Chache hit for {} {}", curr_jolts, jolts);
+            return cache[&(curr_jolts, jolts)];
+        }
+
+        println!("Chache miss for {} {}", curr_jolts, jolts);
+
+        let res = if rest.len() > 3 {
+            enumerate_chains(jolts, &rest[1..], cache)
+                + enumerate_chains(jolts, &rest[2..], cache)
+                + enumerate_chains(jolts, &rest[3..], cache)
+        } else if rest.len() > 2 {
+            enumerate_chains(jolts, &rest[1..], cache) + enumerate_chains(jolts, &rest[2..], cache)
+        } else {
+            enumerate_chains(jolts, &rest[1..], cache)
+        };
+
+        cache.insert((curr_jolts, jolts), res);
+
+        res
+    }
+}
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let file = File::open("inputs/day10.txt")?;
+    let lines = io::BufReader::new(file).lines().map(|l| l.unwrap());
+
+    let mut adapters: Vec<u32> = lines.map(|l| l.parse().unwrap()).collect();
+    adapters.sort();
+    adapters.insert(0, 0);
+    adapters.push(adapters.iter().last().unwrap() + 3);
+
+    let diff_hist: HashMap<u32, u32> =
+        adapters
+            .windows(2)
+            .map(|win| win[1] - win[0])
+            .fold(HashMap::new(), |mut map, x| {
+                map.entry(x).and_modify(|e| *e = *e + 1).or_insert(1);
+                map
+            });
+
+    println!("{:?}", diff_hist);
+    println!("Answer: {}", diff_hist[&1] * diff_hist[&3]);
+
+    let chains = enumerate_chains(0, &adapters, &mut HashMap::new());
+    println!("Number of possible chains: {}", chains);
+
+    Ok(())
+}

src/bin/day5.rs

@@ -61,7 +61,7 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     for pair in seat_ids.windows(2) {
         if pair[1] != pair[0] + 1 {
-            println!("Missing ID: {}", pair[0] + 1 );
+            println!("Missing ID: {}", pair[0] + 1);
             break;
         }
     }