Added day 9

inputs/test.txt

@@ -1,26 +1,26 @@
-pid:087499704 hgt:74in ecl:grn iyr:2012 eyr:2030 byr:1980
-hcl:#623a2f
-
-eyr:2029 ecl:blu cid:129 byr:1989
-iyr:2014 pid:896056539 hcl:#a97842 hgt:165cm
-
-hcl:#888785
-hgt:164cm byr:2001 iyr:2015 cid:88
-pid:545766238 ecl:hzl
-eyr:2022
-
-iyr:2010 hgt:158cm hcl:#b6652a ecl:blu byr:1944 eyr:2021 pid:093154719
-
-eyr:1972 cid:100
-hcl:#18171d ecl:amb hgt:170 pid:186cm iyr:2018 byr:1926
-
-iyr:2019
-hcl:#602927 eyr:1967 hgt:170cm
-ecl:grn pid:012533040 byr:1946
-
-hcl:dab227 iyr:2012
-ecl:brn hgt:182cm pid:021572410 eyr:2020 byr:1992 cid:277
-
-hgt:59cm ecl:zzz
-eyr:2038 hcl:74454a iyr:2023
-pid:3556412378 byr:2007
+133
+281
+137
+134
+154
+148
+150
+161
+179
+211
+181
+182
+215
+203
+217
+232
+233
+237
+234
+241
+267
+254
+256
+257
+270
+403

src/bin/day9.rs

@@ -0,0 +1,60 @@
+use itertools::Itertools;
+use std::error::Error;
+use std::fs::File;
+use std::io::{self, BufRead};
+use std::vec::Vec;
+
+const WIN_LEN: usize = 25;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let file = File::open("inputs/day9.txt")?;
+    let lines = io::BufReader::new(file).lines().map(|l| l.unwrap());
+
+    let numbers: Vec<u64> = lines.map(|l| l.parse().unwrap()).collect();
+
+    let mut target = 0;
+
+    for win in numbers.windows(WIN_LEN + 1) {
+        target = win[WIN_LEN];
+        let canidates = &win[0..WIN_LEN];
+        let mut valid = false;
+
+        for pair in canidates.iter().combinations(2) {
+            //println!("{} + {} = {}", pair[0], pair[1], pair[0] + pair[1]);
+            if pair[0] + pair[1] == target {
+                valid = true;
+                break;
+            }
+        }
+
+        if !valid {
+            break;
+        }
+    }
+
+    println!("Invalid Number: {}", target);
+    let invalid_pos = numbers.iter().position(|n| *n == target).unwrap();
+
+    println!("Target is at: {}", invalid_pos);
+    'sum_outer: for len in 2..invalid_pos {
+        for win in numbers.windows(len) {
+            let sum = win.iter().fold(0, |x, acc| x + acc);
+            if sum == target {
+                println!("Set: {:?}", win);
+                let min = win
+                    .iter()
+                    .fold(*win.first().unwrap(), |x, acc| u64::min(x, *acc));
+
+                let max = win
+                    .iter()
+                    .fold(*win.first().unwrap(), |x, acc| u64::max(x, *acc));
+
+                println!("Answer: {}", min + max);
+
+                break 'sum_outer;
+            }
+        }
+    }
+
+    Ok(())
+}