update example

Author: hackware1993

example/top_sort.dart

@@ -0,0 +1,82 @@
+import 'dart:math';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_constraintlayout/flutter_constraintlayout.dart';
+
+import 'custom_app_bar.dart';
+
+class OpenGrammarExample extends StatelessWidget {
+  const OpenGrammarExample({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: const CustomAppBar(
+        title: 'Open Grammar',
+        codePath: 'example/n_grammar.dart',
+      ),
+      body: ConstraintLayout().open(() {
+        GestureDetector(
+          child: Container(
+            color: Colors.red,
+          ),
+          onTap: () {
+            Random random = Random();
+            var arr = [
+              for (int i = 0; i < 10000000; i++) random.nextInt(4294967296)
+            ];
+            List copy = List.of(arr);
+            Stopwatch stopwatch = Stopwatch()..start();
+            topSort(arr);
+            print("top sort time usage = ${stopwatch.elapsedMicroseconds}");
+            stopwatch = Stopwatch()..start();
+            copy.sort();
+            print(
+                "quick sort time usage = ${stopwatch.elapsedMicroseconds} ${listEquals(arr, copy)}");
+          },
+        ).applyConstraint(
+          size: 200,
+          centerTo: parent,
+        );
+      }),
+    );
+  }
+}
+
+void topSort(List<int> list) {
+  int sum = 0;
+  for (var element in list) {
+    sum += element;
+  }
+  int slot;
+  List<List<int>?> bucket = List.filled(list.length + 1, null);
+  for (final element in list) {
+    slot = ((element / sum) * list.length).toInt();
+    if (slot < 0) {
+      slot = 0;
+    }
+    if (bucket[slot] == null) {
+      bucket[slot] = [];
+    }
+    bucket[slot]!.add(element);
+  }
+  int compare(int left, int right) {
+    return left - right;
+  }
+
+  int index = 0;
+  for (final element in bucket) {
+    if (element != null) {
+      if (element.length > 1) {
+        element.sort(compare);
+      }
+      if (element.isNotEmpty) {
+        for (final element in element) {
+          list[index] = element;
+          index++;
+        }
+      }
+    }
+  }
+}