「🎉」 init(2025): day 1

2024/day02/part2.rs

@@ -0,0 +1,47 @@
+use std::fs;
+
+fn is_ordered(numbers: &[i32]) -> bool
+{
+    let is_increasing = numbers.windows(2).all(|w| w[0] < w[1]);
+    let is_decreasing = numbers.windows(2).all(|w| w[0] > w[1]);
+
+    is_increasing || is_decreasing
+}
+
+fn check_range(numbers: &[i32]) -> bool
+{
+    numbers.windows(2).all(|w| (1..=3).contains(&(w[1] - w[0]).abs()))
+}
+
+fn main() {
+    let content = fs::read_to_string("input.txt")
+        .expect("error with input file.");
+
+    let mut result = 0;
+
+    for lines in content.split('\n')
+    {
+
+        let values: Vec<i32> = lines.split_whitespace().map(|x| x.parse().expect("Invalid number")).collect();
+
+        if is_ordered(&values) && check_range(&values)
+        {
+            result += 1;
+        }
+        else
+        {
+            for i in 0..values.len()
+            {
+                let mut modified_values = values.to_vec();
+                modified_values.remove(i);
+                if is_ordered(&modified_values) && check_range(&modified_values)
+                {
+                    result += 1;
+                    break;
+                }
+            }
+        }
+    }
+
+    println!("{}", result);
+}