Upgrade to Rust 1.88.0 (using let chain)

Author: kwj

rust/README.md

@@ -16,7 +16,7 @@ If you are familiar with Cargo, you can run it directly.
 
 ## Notes
 
-It was confirmed to work with Rust 1.85.0.
+It was confirmed to work with Rust 1.88.0.
 
 I used the following crates and their dependent crates.
 

rust/src/bin/p0026.rs

@@ -16,10 +16,10 @@ fn compute(upper: i64) -> i64 {
         if d <= max_length {
             break;
         }
-        if let Some(tpl @ (length, _)) = find_repetend_length(d) {
-            if length > max_length {
-                (max_length, ans) = tpl;
-            }
+        if let Some(tpl @ (length, _)) = find_repetend_length(d)
+            && length > max_length
+        {
+            (max_length, ans) = tpl;
         }
     }