add 2196

Author: fishercoder1534

Diff for: paginated_contents/algorithms/3rd_thousand/README.md

@@ -107,6 +107,7 @@
 | 2206 | [Divide Array Into Equal Pairs](https://leetcode.com/problems/divide-array-into-equal-pairs/)                                                                                                 | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2206.java)                                       || Easy                                 ||
 | 2201 | [Count Artifacts That Can Be Extracted](https://leetcode.com/problems/count-artifacts-that-can-be-extracted/)                                                                                 | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2201.java)                                       || Medium                               ||
 | 2200 | [Find All K-Distant Indices in an Array](https://leetcode.com/problems/find-all-k-distant-indices-in-an-array/)                                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2200.java)                                       || Easy                                 ||
+| 2196 | [Create Binary Tree From Descriptions](https://leetcode.com/problems/create-binary-tree-from-descriptions/)                                                                                       | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2196.java)                                       || Medium                               | HashTable, Tree
 | 2194 | [Cells in a Range on an Excel Sheet](https://leetcode.com/problems/cells-in-a-range-on-an-excel-sheet/)                                                                                       | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2194.java)                                       || Easy                                 ||
 | 2190 | [Most Frequent Number Following Key In an Array](https://leetcode.com/problems/most-frequent-number-following-key-in-an-array/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2190.java)                                       || Easy                                 ||
 | 2186 | [Minimum Number of Steps to Make Two Strings Anagram II](https://leetcode.com/problems/minimum-number-of-steps-to-make-two-strings-anagram-ii/)                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2186.java)                                       || Medium                               ||

Diff for: src/main/java/com/fishercoder/solutions/thirdthousand/_2196.java

@@ -0,0 +1,40 @@
+package com.fishercoder.solutions.thirdthousand;
+
+import com.fishercoder.common.classes.TreeNode;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+public class _2196 {
+    public static class Solution1 {
+        /**
+         * My completely original solution.
+         */
+        public TreeNode createBinaryTree(int[][] descriptions) {
+            Map<Integer, TreeNode> map = new HashMap<>();
+            Set<Integer> notRootVals = new HashSet<>();
+            for (int[] des : descriptions) {
+                notRootVals.add(des[1]);
+                TreeNode node = map.getOrDefault(des[0], new TreeNode(des[0]));
+                if (des[2] == 1) {
+                    node.left = map.getOrDefault(des[1], new TreeNode(des[1]));
+                    map.put(des[1], node.left);
+                } else {
+                    node.right = map.getOrDefault(des[1], new TreeNode(des[1]));
+                    map.put(des[1], node.right);
+                }
+                map.put(des[0], node);
+            }
+            int rootVal = -1;
+            for (int[] des : descriptions) {
+                if (!notRootVals.contains(des[0])) {
+                    rootVal = des[0];
+                    break;
+                }
+            }
+            return map.get(rootVal);
+        }
+    }
+}

Diff for: src/test/java/com/fishercoder/thirdthousand/_2196Test.java

@@ -0,0 +1,32 @@
+package com.fishercoder.thirdthousand;
+
+import com.fishercoder.common.classes.TreeNode;
+import com.fishercoder.common.utils.TreeUtils;
+import com.fishercoder.solutions.thirdthousand._2196;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+
+import static org.junit.Assert.assertEquals;
+
+public class _2196Test {
+    private static _2196.Solution1 solution1;
+
+    @BeforeEach
+    public void setup() {
+        solution1 = new _2196.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        TreeNode expected = TreeUtils.constructBinaryTree(Arrays.asList(50, 20, 80, 15, 17, 19));
+        TreeUtils.printBinaryTree(expected);
+        TreeNode actual = solution1.createBinaryTree(new int[][]{
+                {20, 15, 1}, {20, 17, 0}, {50, 20, 1}, {50, 80, 0}, {80, 19, 1}
+        });
+        TreeUtils.printBinaryTree(actual);
+        assertEquals(expected, actual);
+    }
+
+}