示例: Java 程序计算树中叶节点的数量
class Node { int item; Node left, right; public Node(int key) { item = key; left = right = null; } } class Main { // root of Tree Node root; Main() { root = null; } // method to count leaf nodes public static int countLeaf(Node node) { if(node == null) { return 0; } // if left and right of the node is null // it is leaf node if (node.left == null && node.right == null) { return 1; } else { return countLeaf(node.left) + countLeaf(node.right); } } public static void main(String[] args) { // create an object of Tree Main tree = new Main(); // create nodes of tree tree.root = new Node(5); tree.root.left = new Node(3); tree.root.right = new Node(8); // create child nodes of left child tree.root.left.left = new Node(2); tree.root.left.right = new Node(4); // create child nodes of right child tree.root.right.left = new Node(7); tree.root.right.right = new Node(9); // call method to count leaf nodes int leafNodes = countLeaf(tree.root); System.out.println("Total Leaf Nodes = " + leafNodes); } }
输出
Total Leaf Nodes = 4
在上面的例子中，我们已经用Java实现了树数据结构。在这里，我们使用递归来计算树中叶节点的数量。
