Add first dart solution

.github/workflows/updateCompletionTable.js

@@ -17,6 +17,7 @@ const FOLDER_TO_LANG = {
     swift: 'Swift',
     cpp: 'C++',
     kotlin: 'Kotlin',
+    dart: 'Dart',
 };
 const PREPEND_PATH = process.argv[2] || './';
 const TEMPLATE_PATH = process.argv[3] || './README_template.md';

dart/0001-two-sum.dart

@@ -0,0 +1,14 @@
+// Time Complexity: O(n)
+// Space Complexity: O(n)
+
+class Solution {
+  List<int> twoSum(List<int> nums, int target) {
+    var map = Map<int, int>();
+    for (int i = 0; i < nums.length; i++) {
+      var x = target - nums[i];
+      if (map.containsKey(x)) return [map[x]!, i];
+      map[nums[i]] = i;
+    }
+    throw "";
+  }
+}

dart/0036-valid-sudoku.dart

@@ -0,0 +1,31 @@
+// As the board size is fixed
+// it will result in the following
+// Time Complexity: O(1)
+// Space Complexity: O(1)
+
+class Solution {
+  bool isValidSudoku(List<List<String>> board) {
+    var rows = List.filled(9, 0);
+    var cols = List.filled(9, 0);
+    var grids = List.filled(9, 0);
+
+    for (int r = 0; r < 9; r++) {
+      for (int c = 0; c < 9; c++) {
+        if (board[r][c] == ".") continue;
+
+        var idx = int.parse(board[r][c]) - 1;
+
+        if (rows[r] & 1 << idx != 0) return false;
+        rows[r] |= 1 << idx;
+
+        if (cols[c] & 1 << idx != 0) return false;
+        cols[c] |= 1 << idx;
+
+        if (grids[r ~/ 3 * 3 + c ~/ 3] & 1 << idx != 0) return false;
+        grids[r ~/ 3 * 3 + c ~/ 3] |= 1 << idx;
+      }
+    }
+
+    return true;
+  }
+}

dart/0049-group-anagrams.dart

@@ -0,0 +1,23 @@
+// Time Complexity: O(n * m)
+// Space Complexity: O(n * m)
+
+class Solution {
+  List<List<String>> groupAnagrams(List<String> strs) {
+    var map = Map<String, List<String>>();
+
+    for (var str in strs) {
+      var count = List.filled(26, 0);
+      for (int i = 0; i < str.length; i++) {
+        count[str[i].codeUnitAt(0) - 'a'.codeUnitAt(0)]++;
+      }
+      var key = count.join("#");
+      if (map.containsKey(key)) {
+        map[key]!.add(str);
+        continue;
+      }
+      map[key] = [str];
+    }
+
+    return List.from(map.values);
+  }
+}

dart/0217-contains-duplicate.dart

@@ -0,0 +1,15 @@
+// Time Complexity: O(n)
+// Space Complexity: O(n)
+
+class Solution {
+  bool containsDuplicate(List<int> nums) {
+    Set<int> hashSet = Set<int>();
+    for (int n in nums) {
+      if (hashSet.contains(n)) {
+        return true;
+      }
+      hashSet.add(n);
+    }
+    return false;
+  }
+}

dart/0242-valid-anagram.dart

@@ -0,0 +1,24 @@
+// Time Complexity: O(s + t)
+// Space Complexity: O(1)
+
+class Solution {
+  bool isAnagram(String s, String t) {
+    if (s.length != t.length) return false;
+
+    final counter = List.filled(26, 0);
+
+    for (int i = 0; i < s.length; i++) {
+      counter[s[i].codeUnitAt(0) - 'a'.codeUnitAt(0)]++;
+    }
+
+    for (int i = 0; i < t.length; i++) {
+      counter[t[i].codeUnitAt(0) - 'a'.codeUnitAt(0)]--;
+    }
+
+    for (int val in counter) {
+      if (val != 0) return false;
+    }
+
+    return true;
+  }
+}

updateSiteData.js

@@ -71,6 +71,11 @@ const languages = [
         directory: 'scala',
         extension: 'scala'
     },
+    {
+        name: 'Dart',
+        directory: 'dart',
+        extension: 'dart'
+    },
 ]
 
 // Rename files to match leetcode url path, and normalize problem number to four digits.

verifySiteData.js

@@ -71,6 +71,11 @@ const languageMap = {
         directory: 'scala',
         extension: 'scala'
     },
+    dart: {
+        name: 'Dart',
+        directory: 'dart',
+        extension: 'dart'
+    },
 };
 
 const GITHUB_BASE_URL = 'https://github.com/neetcode-gh/leetcode/blob/main';