Added AOC 2020 day 03 - 14

www/statics/aoc/2020/09_solution.rs

@@ -0,0 +1,91 @@
+use crate::common::AdventOfCodeDay;
+
+
+use std::collections::HashSet;
+
+pub struct Day09 {
+    input: Vec<u64>,
+}
+
+impl Day09 {
+    pub fn new() -> Self {
+        let input_bytes = include_bytes!("../res/09_input.txt");
+        let input_str = String::from_utf8_lossy(input_bytes);
+        
+        let data = input_str
+                       .lines()
+                        .map(|p| p.parse::<u64>().unwrap())
+                        .collect::<Vec<u64>>();
+
+        Self {
+            input: data
+        }
+    }
+
+    fn all_combinations(data: Vec<&u64>) -> HashSet<u64> {
+        let mut hs: HashSet<u64> = HashSet::new();
+
+        for i1 in 0..24 {
+            for i2 in (i1+1)..25 {
+                hs.insert(data[i1] + data[i2]);
+            }
+        }
+
+        return hs;
+    }
+
+    fn find_invalid(&self) -> u64 {
+        for i in 25..self.input.len() {
+            let comb = Day09::all_combinations(self.input.iter().skip(i-25).take(25).collect());
+
+            if !comb.contains(&self.input[i]) {
+                return self.input[i];
+            }
+        }
+
+        panic!();
+    }
+}
+
+impl AdventOfCodeDay for Day09 {
+
+    fn task_1(&self) -> String {
+        return self.find_invalid().to_string();
+    }
+
+    fn task_2(&self) -> String  {
+        let target = self.find_invalid();
+
+        let mut sum  = self.input[0];
+        let mut idx1 = 0; //inclusive
+        let mut idx2 = 0; //inclusive
+
+        loop {
+            if sum == target {
+                
+                verboseln!("[{}..{}] [[{:?}]] = {} ({})", 
+                            idx1, 
+                            idx2, 
+                            self.input.iter().skip(idx1).take(idx2-idx1+1).collect::<Vec<&u64>>(), 
+                            self.input.iter().skip(idx1).take(idx2-idx1+1).sum::<u64>(),
+                            target);
+
+
+                return (self.input.iter().skip(idx1).take(idx2-idx1+1).min().unwrap() + self.input.iter().skip(idx1).take(idx2-idx1+1).max().unwrap()).to_string();
+
+            } else if sum < target {
+
+                idx2 += 1;
+                sum  += self.input[idx2];
+
+            } else if sum > target {
+
+                sum  -= self.input[idx1];
+                idx1 += 1;
+
+            }
+
+            verboseln!("[{}..{}] = {}", idx1, idx2, sum);
+        }
+    }
+}