From 3b877bf4cc667eb8bcc787d145203600a4dba2d2 Mon Sep 17 00:00:00 2001
From: Prefetch
Date: Sat, 25 Feb 2023 11:41:27 +0100
Subject: Initial commit

---
 d03/src/main.rs | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 d03/src/main.rs

(limited to 'd03/src')

diff --git a/d03/src/main.rs b/d03/src/main.rs
new file mode 100644
index 0000000..d168a44
--- /dev/null
+++ b/d03/src/main.rs
@@ -0,0 +1,89 @@
+use std::fs;
+
+fn solve_part1(rows: &Vec<Vec<usize>>) -> usize {
+    let mut num_valid: usize = 0;
+
+    for row in rows {
+        let mut sides = row.clone();
+
+        sides.sort();
+        if sides[0] + sides[1] > sides[2] {
+            num_valid += 1;
+        }
+    }
+
+    num_valid
+}
+
+fn solve_part2(rows: &Vec<Vec<usize>>) -> usize {
+    let mut num_valid: usize = 0;
+
+    // For each 3 consecutive rows of data
+    for i in 0..(rows.len() / 3) {
+        // For each of the 3 numbers per row
+        for j in 0..3 {
+            let mut sides = Vec::new();
+            // For each row in this group of 3 rows
+            for k in 0..3 {
+                sides.push(rows[3 * i + k][j]);
+            }
+
+            sides.sort();
+            if sides[0] + sides[1] > sides[2] {
+                num_valid += 1;
+            }
+        }
+    }
+
+    num_valid
+}
+
+fn main() {
+    // Read and parse triangle data from input text file
+    let input = fs::read_to_string("input.txt").unwrap();
+    let lines: Vec<&str> = input.lines().collect();
+    let words: Vec<Vec<&str>> = lines
+        .into_iter()
+        .map(|l| l.split_ascii_whitespace().collect())
+        .collect();
+    let rows: Vec<Vec<usize>> = words
+        .into_iter()
+        .map(|w123| w123
+            .into_iter()
+            .map(|s| s.parse().unwrap())
+            .collect())
+        .collect();
+
+    // Part 1 gives 993 for me
+    println!("Part 1 solution: {}", solve_part1(&rows));
+
+    // Part 2 gives 1849 for me
+    println!("Part 2 solution: {}", solve_part2(&rows));
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn part1_example1() {
+        let rows = vec![
+            vec![5, 10, 25],
+            vec![3,  4,  5],
+        ];
+        assert_eq!(solve_part1(&rows), 1);
+    }
+
+    #[test]
+    fn part2_example1() {
+        let rows = vec![
+            vec![101, 301, 501],
+            vec![102, 302, 502],
+            vec![103, 303, 503],
+            vec![201, 401, 601],
+            vec![202, 402, 602],
+            vec![203, 403, 603],
+        ];
+        assert_eq!(solve_part2(&rows), 6);
+    }
+}
-- 
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