FunWithTreesArrayToTree.java

import java.util.*;

public class Solution {
    
    static TreeNode arrayToTree(int[] array) {
      TreeNode root = null;   
      if(array.length > 0){        
        Queue<TreeNode> queue = new LinkedList<TreeNode>();    
        TreeNode treeNode = new TreeNode(array[0]);
        queue.add(treeNode);
        root = treeNode;
        int index=0;
        while(!queue.isEmpty()) {
          TreeNode iterate = queue.poll();
          index++;
          if(index < array.length) {
            TreeNode left = new TreeNode(array[index]);        
            queue.add(left);
            iterate.left = left;
          }
          
          index++;
          if(index < array.length) {
             TreeNode right = new TreeNode(array[index]);
             queue.add(right);
             iterate.right = right;
          }          
        }        
      }
      return root;
    }
}