problem 6

src/main.rs

@@ -6,12 +6,14 @@ use crate::problem2::lib::Problem2;
 use crate::problem3::lib::Problem3;
 use crate::problem4::lib::Problem4;
 use crate::problem5::lib::Problem5;
+use crate::problem6::lib::Problem6;
 
 mod problem1;
 mod problem2;
 mod problem3;
 mod problem4;
 mod problem5;
+mod problem6;
 mod util;
 
 
@@ -41,7 +43,11 @@ fn main() {
     // problem4.run_part1();
     // problem4.run_part2();
 
-    let problem5 = Problem5::new(&util::get_problem(5));
-    problem5.run_part1();
-    problem5.run_part2();
+    // let problem5 = Problem5::new(&util::get_problem(5));
+    // problem5.run_part1();
+    // problem5.run_part2();
+
+    let problem6 = Problem6::new(&util::get_problem(6));
+    problem6.run_part1();
+    problem6.run_part2();
 }

src/problem6/lib.rs

@@ -0,0 +1,52 @@
+/*
+Specifically, they need you to find the two entries that sum to 2020 and then multiply those two numbers together.
+*/
+
+use crate::Problem;
+use std::collections::HashSet;
+
+pub struct Problem6 {
+    groups: Vec<HashSet<char>>,
+}
+
+
+impl Problem6 {}
+
+impl Problem for Problem6 {
+    fn new(input: &String) -> Self {
+        Problem6 {
+            groups: input
+                .split("\n\n")
+                .filter_map(|s| {
+                    let s = s.trim().split("\n");
+                    let mut sets = Vec::new();
+                    for i in s {
+                        let v : HashSet<char> = i.chars().filter_map(|c| {
+                            if c.is_whitespace() {
+                                None
+                            } else {
+                                Some(c)
+                            }
+                        }).collect::<HashSet<char>>();
+                        sets.push(v);
+                    }
+                    let mut iter = sets.iter();
+                    let intersection : HashSet<char> =
+                        iter.next().map(|set| iter.fold(set.clone(), |set1, set2| set1.intersection(set2).map(|c| *c).collect())).unwrap().clone();
+                    Some(intersection)
+                }).collect(),
+        }
+    }
+
+    fn run_part1(&self) {
+        let mut v = 0;
+        for i in &self.groups {
+            v += i.len();
+        }
+        println!("{}\n{:?}", v, self.groups);
+    }
+
+    fn run_part2(&self) {
+    }
+}
+

src/problem6/mod.rs

@@ -0,0 +1 @@
+pub mod lib;