Day 7 part 1

2024/rust/src/day7.rs

@@ -0,0 +1,66 @@
+mod prelude;
+use std::slice::Windows;
+
+pub use crate::prelude::*;
+
+fn main() {
+    let input = day_input(7);
+    show_answers(sum_possibly_valid_tests(&input), 0);
+}
+
+fn sum_possibly_valid_tests(input: &str) -> usize {
+    let mut sum = 0;
+    for l in input.lines() {
+        let (target, operands) = l.split_once(':').unwrap();
+        let target: usize = target.parse().unwrap();
+        println!("{target}");
+        let operands: Vec<usize> = operands
+            .trim()
+            .split(" ")
+            .map(|s| s.parse().unwrap())
+            .collect();
+        println!("{operands:?}");
+        if operands
+            .iter()
+            .skip(1)
+            .fold(vec![operands[0]], add_and_mul)
+            .iter()
+            .any(|n| *n == target)
+        {
+            sum += target;
+        }
+    }
+    sum
+}
+
+fn add_and_mul(lefts: Vec<usize>, right: &usize) -> Vec<usize> {
+    let mut result = vec![];
+    for left in lefts {
+        result.push(left + right);
+        result.push(left * right);
+    }
+    result
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test() {
+        assert_eq!(
+            sum_possibly_valid_tests(
+                "190: 10 19
+3267: 81 40 27
+83: 17 5
+156: 15 6
+7290: 6 8 6 15
+161011: 16 10 13
+192: 17 8 14
+21037: 9 7 18 13
+292: 11 6 16 20"
+            ),
+            3749
+        )
+    }
+}