/**  
         * 计算二叉树中叶子结点个数  
         *  
         * @className: NumberOfLeavesInBT  
         * @author: Max Solider  
         * @date: 2023-06-11 19:29  
         */public class NumberOfLeavesInBT {  

            public static int numberOfLeavesInBT(BinaryTreeNode root) {  
                if (root == null) {  
                    return 0;  
                }  
                int count = 0;  
                ArrayQueue queue = new ArrayQueue(10);  
                queue.enQueue(root);  
                while (!queue.isEmpty()) {  
                    BinaryTreeNode tmp = (BinaryTreeNode) queue.deQueue();  
                    if (tmp.getLeft() == null && tmp.getRight() == null) {  
                        count ++;  
                    }  
                    if (tmp.getLeft() != null) {  
                        queue.enQueue(tmp.getLeft());  
                    }  
                    if (tmp.getRight() != null) {  
                        queue.enQueue(tmp.getRight());  
                    }  
                }  
                return count;  
            }  
        }