Use split_last

Author: EbbDrop

src/day7.rs

@@ -1,28 +1,25 @@
-use std::{hint::unreachable_unchecked, num::NonZero};
+use std::num::NonZero;
 
 use aoc_runner_derive::aoc;
 
-fn search(target: u64, v: &[NonZero<u64>]) -> bool {
-    match v {
-        [] => unsafe { unreachable_unchecked() },
-        [rest @ .., last] => {
-            let last = last.get();
-            if rest.is_empty() {
-                return target == last;
-            }
-            if last > target {
-                return false;
-            }
+pub fn search(target: u64, v: &[NonZero<u64>]) -> bool {
+    let (last, rest) = unsafe { v.split_last().unwrap_unchecked() };
 
-            if target % last == 0 {
-                if search(target / last, rest) {
-                    return true;
-                }
-            }
+    let last = last.get();
+    if rest.is_empty() {
+        return target == last;
+    }
+    if last > target {
+        return false;
+    }
 
-            return search(target - last, rest);
+    if target % last == 0 {
+        if search(target / last, rest) {
+            return true;
         }
     }
+
+    return search(target - last, rest);
 }
 
 #[aoc(day7, part1)]
@@ -73,40 +70,37 @@ unsafe fn part1_inner(s: &str) -> u64 {
     sum
 }
 
-fn search_part2(target: u64, v: &[NonZero<u64>]) -> bool {
-    match v {
-        [] => unsafe { unreachable_unchecked() },
-        [rest @ .., last] => {
-            let last = last.get();
-            if rest.is_empty() {
-                return target == last;
-            }
-            if last > target {
-                return false;
-            }
+pub fn search_part2(target: u64, v: &[NonZero<u64>]) -> bool {
+    let (last, rest) = unsafe { v.split_last().unwrap_unchecked() };
 
-            if target % last == 0 {
-                if search_part2(target / last, rest) {
-                    return true;
-                }
-            }
+    let last = last.get();
+    if rest.is_empty() {
+        return target == last;
+    }
+    if last > target {
+        return false;
+    }
 
-            let size = if last >= 100 {
-                1000
-            } else if last >= 10 {
-                100
-            } else {
-                10
-            };
-            if (target - last) % size == 0 {
-                if search_part2((target - last) / size, rest) {
-                    return true;
-                }
-            }
+    if target % last == 0 {
+        if search_part2(target / last, rest) {
+            return true;
+        }
+    }
 
-            return search_part2(target - last, rest);
+    let size = if last >= 100 {
+        1000
+    } else if last >= 10 {
+        100
+    } else {
+        10
+    };
+    if (target - last) % size == 0 {
+        if search_part2((target - last) / size, rest) {
+            return true;
         }
     }
+
+    return search_part2(target - last, rest);
 }
 
 #[aoc(day7, part2)]