add 919

Author: fishercoder1534

Diff for: paginated_contents/algorithms/1st_thousand/README.md

@@ -44,6 +44,7 @@
 | 923 | [3Sum With Multiplicity](https://leetcode.com/problems/3sum-with-multiplicity/)                                                                                                               | [Solution](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/firstthousand/_923.java)                                                                  |                                                                               | Medium                           | Two Pointers                                                         
 | 922 | [Sort Array By Parity II](https://leetcode.com/problems/sort-array-by-parity-ii/)                                                                                                             | [Solution](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/firstthousand/_922.java)                                                                  |                                                                               | Easy                             |
 | 921 | [Minimum Add to Make Parentheses Valid](https://leetcode.com/problems/minimum-add-to-make-parentheses-valid/)                                                                                 | [Solution](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/firstthousand/_921.java)                                                                  |                                                                               | Medium                           | Stack, Greedy                                                        
+| 919 | [Complete Binary Tree Inserter](https://leetcode.com/problems/complete-binary-tree-inserter/)                                                                                                 | [Solution](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/firstthousand/_919.java)                                                                  |                                                                               | Medium                           | Tree, BFS
 | 918 | [Maximum Sum Circular Subarray](https://leetcode.com/problems/maximum-sum-circular-subarray/)                                                                                                 | [Solution](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/firstthousand/_918.java)                                                                  |                                                                               | Medium                           | Array, DP, Monotonic Queue                                           
 | 917 | [Reverse Only Letters](https://leetcode.com/problems/reverse-only-letters/)                                                                                                                   | [Solution](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/firstthousand/_917.java)                                                                  |                                                                               | Easy                             |
 | 914 | [X of a Kind in a Deck of Cards](https://leetcode.com/problems/x-of-a-kind-in-a-deck-of-cards/)                                                                                               | [Solution](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/firstthousand/_914.java)                                                                  |                                                                               | Easy                             |

Diff for: src/main/java/com/fishercoder/solutions/firstthousand/_919.java

@@ -0,0 +1,61 @@
+package com.fishercoder.solutions.firstthousand;
+
+import com.fishercoder.common.classes.TreeNode;
+
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Queue;
+
+public class _919 {
+    public static class Solution1 {
+        /**
+         * My completely original solution.
+         * Beats 98.11% submissions.
+         */
+        public static class CBTInserter {
+            private Map<Integer, TreeNode> indexMap;
+            private int index;
+            private TreeNode root;
+
+            public CBTInserter(TreeNode root) {
+                this.indexMap = new HashMap<>();
+                this.index = 1;
+                this.root = root;
+                Queue<TreeNode> q = new LinkedList<>();
+                q.offer(root);
+                while (!q.isEmpty()) {
+                    int size = q.size();
+                    for (int i = 0; i < size; i++) {
+                        TreeNode curr = q.poll();
+                        indexMap.put(index++, curr);
+                        if (curr.left != null) {
+                            q.offer(curr.left);
+                        }
+                        if (curr.right != null) {
+                            q.offer(curr.right);
+                        }
+                    }
+                }
+            }
+
+            public int insert(int val) {
+                int parentIndex = index / 2;
+                TreeNode parentNode = indexMap.get(parentIndex);
+                TreeNode childNode = new TreeNode(val);
+                if (index % 2 == 0) {
+                    parentNode.left = childNode;
+                } else {
+                    parentNode.right = childNode;
+                }
+                indexMap.put(index++, childNode);
+                indexMap.put(parentIndex, parentNode);
+                return parentNode.val;
+            }
+
+            public TreeNode get_root() {
+                return root;
+            }
+        }
+    }
+}

Diff for: src/test/java/com/fishercoder/firstthousand/_919Test.java

@@ -0,0 +1,28 @@
+package com.fishercoder.firstthousand;
+
+import com.fishercoder.common.classes.TreeNode;
+import com.fishercoder.common.utils.TreeUtils;
+import com.fishercoder.solutions.firstthousand._919;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class _919Test {
+    private static _919.Solution1.CBTInserter cbtInserter;
+
+    @BeforeEach
+    public void setup() {
+    }
+
+    @Test
+    public void test1() {
+        TreeNode root = TreeUtils.constructBinaryTree(Arrays.asList(5, 14, 4, 5, 14, 16, 16, 20, 7, 13));
+        cbtInserter = new _919.Solution1.CBTInserter(root);
+        TreeUtils.printBinaryTree(cbtInserter.get_root());
+        assertEquals(14, cbtInserter.insert(8));
+    }
+
+}