Implement 2025 - Day 1 - Part 2

2025/01.rs

@@ -38,26 +38,44 @@ fn main() {
 
     println!("Rotations: {:#?}", rotations);
 
-    let mut count = 0;
+    let mut count: usize = 0;
 
     let mut state: isize = 50;
     for rot in rotations.iter() {
+        if rot.amount >= 100 {
+            count += rot.amount / 100;
+        }
+
+        let amount = rot.amount % 100;
+        if amount == 0 {
+            continue;
+        }
+
         match rot.direction {
             Direction::Left => {
-                state = state.strict_sub_unsigned(rot.amount);
+                if state != 0 && amount > state as usize {
-                state = state.strict_rem_euclid(100);
+                    count += 1;
                 }
-            Direction::Right => {
-                state = state.strict_add_unsigned(rot.amount);
-                state = state.strict_rem_euclid(100);
-            }
-        };
 
-        println!("Applying {:?} => {}", rot, state);
+                state = state.strict_sub_unsigned(amount);
+                state = state.strict_rem_euclid(100);
+
                 if state == 0 {
                     count += 1;
                 }
             }
+            Direction::Right => {
+                state = state.strict_add_unsigned(amount);
+                if state >= 100 {
+                    count += 1;
+                }
+
+                state = state.strict_rem_euclid(100);
+            }
+        };
+
+        println!("Applying {:?} => {} ({})", rot, state, count);
+    }
 
     println!("Result: {}", count);
 }