'modify'

Author: tianqing.liang

06-Recursion/Solution3.dart

@@ -14,9 +14,9 @@ class Solution3{
       }
     }
     return dummyHead.next;
-    if(head == null){
-      return head;
-    }
+//    if(head == null){
+//      return head;
+//    }
 //    ListNode? res = removeElements(head.next!, val);
 //    if(head.val == val){
 //      return res;

08-QuickSort-More/QuickSort2way.dart

@@ -5,7 +5,7 @@ import 'dart:math';
  * 二路快排
  */
 class QuickSort2way {
-  _QuickSort2way() {}
+  QuickSort2way() {}
 
   static sort2ways(List arr) {
     Random rnd = new Random();

08-QuickSort-More/QuickSort3way.dart

@@ -4,7 +4,7 @@ import 'dart:math';
  * 三路快排
  */
 class QuickSort3way {
-  _QuickSort3way() {}
+  QuickSort3way() {}
 
   static sort3ways(List arr) {
     Random rnd = new Random();

08-QuickSort/QuickSort.dart

@@ -1,7 +1,7 @@
 import 'ArrayGenerator.dart';
 import 'dart:math';
 class QuickSort{
-  _QuickSort(){
+  QuickSort(){
   }
   static sort(List arr){
     _sortDetail(arr,0,arr.length-1);

09-Binary-Search-More/up/BinarySearchFloor.dart

@@ -4,7 +4,7 @@ import 'ArrayGenerator.dart';
  * 二分搜索
  */
 class BinarySearch {
-  _BinarySearch() {}
+  BinarySearch() {}
 
   static int search<T>(List data, T target) {
     int left = 0, right = data.length - 1;

09-Binary-Search-More/up/BinarySearchLowerCeil.dart

@@ -4,7 +4,7 @@ import 'ArrayGenerator.dart';
  * 二分搜索
  */
 class BinarySearch {
-  _BinarySearch() {}
+  BinarySearch() {}
 
   static int search<T>(List data, T target) {
     int left = 0, right = data.length - 1;

09-Binary-Search-More/up/BinarySearchUp.dart

@@ -5,7 +5,7 @@ import 'ArrayGenerator.dart';
  */
 class BinarySearch{
 
-  _BinarySearch(){}
+  BinarySearch(){}
 
   static int search<T>(List data,T target){
 

09-Binary-Search/BinarySearchR.dart

@@ -5,7 +5,7 @@ import 'ArrayGenerator.dart';
  */
 class BinarySearch{
 
-  _BinarySearch(){}
+  BinarySearch(){}
 
   static int search<T>(List data,T target){
 

10-Binary-Search-Tree/BST.dart

@@ -266,7 +266,7 @@ class BST<T extends Comparable<T>> {
     if( node == null )
       return null;
 
-    if( e!.compareTo(node.e!) < 0 ){
+    if( e.compareTo(node.e!) < 0 ){
       node.left = _removeNode(node.left! , e);
       return node;
     }

17-Trie/Trie.dart

@@ -45,7 +45,7 @@ class Trie {
   // 查询是否在Trie中有单词以prefix为前缀
   bool isPrefix(String prefix){
     _Node? cur = _root;
-    for(int i = 0 ; i < prefix!.length ; i ++){
+    for(int i = 0 ; i < prefix.length ; i ++){
       String c = prefix[i];
       if(cur!.next![c] == null){
         return false;

20-Red-Black-Tree/Main2.dart

@@ -1,4 +1,3 @@
-import 'FileOperator.dart';
 import 'BST.dart';
 import 'AVLTree.dart';
 import 'dart:math';

20-Red-Black-Tree/RBTree.dart

@@ -1,4 +1,3 @@
-import 'dart:math';
 import 'FileOperator.dart';
 
 /**

21-Hash-Table/Main.dart

@@ -1,6 +1,5 @@
 import 'dart:collection';
 import 'FileOperator.dart';
-import 'HashTable.dart';
 import 'HashTableSec.dart';
 
 void main() async{

21-Hash-Table/RBTree.dart

@@ -1,4 +1,3 @@
-import 'dart:math';
 import 'FileOperator.dart';
 
 /**

21-Hash-Table/Solution.dart

@@ -1,4 +1,3 @@
-import 'dart:collection';
 
 /**
  * dart中无类型提升

22-CountingSort-And-RadixSort/Solution.dart

@@ -1,7 +1,7 @@
 class Solution {
   sortColors(List<int> nums) {
     List? cnt = List.filled(3, 0, growable: true);
-    for (int num in nums!) {
+    for (int num in nums) {
       cnt[num]++;}
 
     for (int i = 0; i < cnt[0]; i++) {
@@ -20,7 +20,7 @@ class Solution {
     int R = 3;
 
     List? cnt = List.filled(3, 0, growable: true);
-    for (int num in nums!) {
+    for (int num in nums) {
       cnt[num]++;
     }
 

23-MSDSort-And-BucketSort/BucketSort.dart

@@ -1,5 +1,4 @@
 import 'ArrayGenerator.dart';
-import 'SortingHelper.dart';
 import 'dart:math';
 
 class BucketSort {

23-MSDSort-And-BucketSort/SortingHelper.dart

@@ -43,6 +43,6 @@ class SortingHelper {
     print("开始时间：$startTime : 结束时间:$endTime");
     double time = (endTime - startTime) / 1000.0;
     if (!SortingHelper.isSorted(arr)) throw new Exception(sortname + " failed");
-    print("$sortname , n = ${arr!.length}: $time s");
+    print("$sortname , n = ${arr.length}: $time s");
   }
 }