Add figures to replace_linear_by_hashing.md

codes/dart/chapter_computational_complexity/leetcode_two_sum.dart

@@ -1,47 +0,0 @@
-/**
- * File: leetcode_two_sum.dart
- * Created Time: 2023-2-11
- * Author: Jefferson (JeffersonHuang77@gmail.com)
- */
-
-import 'dart:collection';
-
-/* 方法一： 暴力枚举 */
-List<int> twoSumBruteForce(List<int> nums, int target) {
-  int size = nums.length;
-  for (var i = 0; i < size - 1; i++) {
-    for (var j = i + 1; j < size; j++) {
-      if (nums[i] + nums[j] == target) return [i, j];
-    }
-  }
-  return [0];
-}
-
-/* 方法二： 辅助哈希表 */
-List<int> twoSumHashTable(List<int> nums, int target) {
-  int size = nums.length;
-  Map<int, int> dic = HashMap();
-  for (var i = 0; i < size; i++) {
-    if (dic.containsKey(target - nums[i])) {
-      return [dic[target - nums[i]]!, i];
-    }
-    dic.putIfAbsent(nums[i], () => i);
-  }
-  return [0];
-}
-
-/* Driver Code */
-int main() {
-  // ======= Test Case =======
-  List<int> nums = [2, 7, 11, 15];
-  int target = 9;
-
-  // ====== Driver Code ======
-  // 方法一
-  List<int> res = twoSumBruteForce(nums, target);
-  print('方法一 res = $res');
-  // 方法二
-  res = twoSumHashTable(nums, target);
-  print('方法二 res = $res');
-  return 0;
-}