AK: Add a shuffle utility function

This implements a shuffle function in AK/Random.h which works on any container with size() and curly brace operators. It uses fisher-yates shuffle.
Author: https://github.com/kuzux Commit: https://github.com/SerenityOS/serenity/commit/1cdd3bb74f Pull-request: https://github.com/SerenityOS/serenity/pull/16386 Reviewed-by: https://github.com/AtkinsSJ
2022-12-09 16:46:13 +03:00 · 2022-12-09 16:46:13 +03:00 · 1cdd3bb74f · 2024-07-17 03:21:31 +09:00
commit 1cdd3bb74f
parent 30abd47099
1 changed files with 12 additions and 0 deletions
--- a/AK/Random.h
+++ b/AK/Random.h
@ -7,6 +7,7 @@
 #pragma once

 #include <AK/Platform.h>
+#include <AK/StdLibExtras.h>
 #include <AK/Types.h>

 #if defined(AK_OS_SERENITY) || defined(AK_OS_ANDROID)
@ -52,10 +53,21 @@ inline T get_random()

 u32 get_random_uniform(u32 max_bounds);

+template<typename Collection>
+inline void shuffle(Collection& collection)
+{
+    // Fisher-Yates shuffle
+    for (size_t i = collection.size() - 1; i >= 1; --i) {
+        size_t j = get_random_uniform(i + 1);
+        AK::swap(collection[i], collection[j]);
+    }
+}
+
 }

 #if USING_AK_GLOBALLY
 using AK::fill_with_random;
 using AK::get_random;
 using AK::get_random_uniform;
+using AK::shuffle;
 #endif