Implement 2016 day 22 part 1. Again.

2016/src/day22.rs

@@ -0,0 +1,69 @@
+use std::io::Read;
+
+use common::Solution;
+use std::io::BufReader;
+use regex::Regex;
+use std::io::BufRead;
+
+type Coordinate = (usize, usize);
+
+#[derive(Debug, Eq, PartialEq, Copy, Clone, Default)]
+struct Node {
+    pos: Coordinate,
+    capacity: usize,
+    used: usize,
+}
+
+impl Node {
+    fn fits(self, other: Node) -> bool {
+        self.capacity - self.used >= other.used
+    }
+}
+
+#[derive(Default)]
+pub struct Day22 {
+    nodes: Vec<Node>,
+}
+
+impl Day22 {
+    pub fn new() -> Self {
+        Default::default()
+    }
+
+    fn read_input(&mut self, input: &mut Read) {
+        let reader = BufReader::new(input);
+        let matcher = Regex::new(r"/dev/grid/node-x(\d+)-y(\d+)(?:\s+)(\d+)T(?:\s+)+(\d+)T").unwrap();
+
+        for line in reader.lines() {
+            let line = line.unwrap();
+            let node = match matcher.captures(&line) {
+                Some(captures) => Node {
+                    pos: (captures[1].parse().unwrap(), captures[2].parse().unwrap()),
+                    capacity: captures[3].parse().unwrap(),
+                    used: captures[4].parse().unwrap(),
+                },
+
+                None => continue
+            };
+
+            self.nodes.push(node)
+        }
+
+        assert_ne!(0, self.nodes.len())
+    }
+}
+
+impl Solution for Day22 {
+    fn part1(&mut self, input: &mut Read) -> String {
+        self.read_input(input);
+
+        let fitting = iproduct!(&self.nodes, &self.nodes)
+            .filter(|&(_, b)| b.used > 0)
+            .filter(|&(a, b)| a != b)
+            .filter(|&(a, b)| a.fits(*b))
+            .count();
+
+
+        fitting.to_string()
+    }
+}