start 2016 day03 and start Combinations Iterator implementation

src/lib.rs

@@ -1,10 +1,12 @@
 pub mod util {
     pub mod grid;
     pub mod index;
+    pub mod iter;
     pub mod parse;
 }
 
 pub mod year2016 {
     pub mod day01;
     pub mod day02;
+    pub mod day03;
 }

src/main.rs

@@ -1,4 +1,4 @@
-use std::time::{Instant, Duration};
+use std::time::{Duration, Instant};
 
 use aoc::util::parse::ParseExt;
 
@@ -69,5 +69,9 @@ fn solutions() -> impl Iterator<Item = Solution> {
 }
 
 fn year2016() -> Vec<Solution> {
-    vec![solution!(year2016, day01), solution!(year2016, day02)]
+    vec![
+        solution!(year2016, day01),
+        solution!(year2016, day02),
+        solution!(year2016, day03),
+    ]
 }

src/util/iter.rs

@@ -0,0 +1,27 @@
+pub struct Combinations<I: Iterator> {
+    indices: Vec<usize>,
+    size: usize,
+    pool: Vec<I::Item>,
+    first: bool,
+}
+
+impl<I: Iterator> Combinations<I> {
+    pub fn new(iter: I, comb: usize) -> Self {
+        let pool: Vec<I::Item> = iter.collect();
+
+        Self {
+            indices: Vec::with_capacity(comb),
+            size: pool.len(),
+            pool,
+            first: true,
+        }
+    }
+}
+
+impl<I: Iterator> Iterator for Combinations<I> {
+    type Item = I::Item;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        todo!()
+    }
+}

src/year2016/day03.rs

@@ -0,0 +1,21 @@
+use crate::util::parse::ParseExt;
+
+pub fn part1(input: &str) -> impl std::fmt::Display {
+    let vec: Vec<Vec<u32>> = input.lines().map(|s| s.u32s().collect()).combin;
+
+    ""
+}
+
+pub fn part2(input: &str) -> impl std::fmt::Display {
+    ""
+}
+
+#[test]
+fn test_part1() {
+    assert_eq!("0", part1("5 10 25").to_string())
+}
+
+#[test]
+fn test_part2() {
+    assert_eq!("", part2("").to_string())
+}