用c语言编写求叶子结点的算法

以下是用C语言编写求二叉树叶子结点数量的算法：

#include <stdio.h>
#include <stdlib.h>

// 二叉树结点结构体
typedef struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
} TreeNode;

// 创建二叉树
TreeNode* createTree() {
    TreeNode *root = (TreeNode*)malloc(sizeof(TreeNode));
    root->val = 1;
    root->left = (TreeNode*)malloc(sizeof(TreeNode));
    root->left->val = 2;
    root->left->left = (TreeNode*)malloc(sizeof(TreeNode));
    root->left->left->val = 4;
    root->left->left->left = NULL;
    root->left->left->right = NULL;
    root->left->right = (TreeNode*)malloc(sizeof(TreeNode));
    root->left->right->val = 5;
    root->left->right->left = NULL;
    root->left->right->right = NULL;
    root->right = (TreeNode*)malloc(sizeof(TreeNode));
    root->right->val = 3;
    root->right->left = (TreeNode*)malloc(sizeof(TreeNode));
    root->right->left->val = 6;
    root->right->left->left = NULL;
    root->right->left->right = NULL;
    root->right->right = (TreeNode*)malloc(sizeof(TreeNode));
    root->right->right->val = 7;
    root->right->right->left = NULL;
    root->right->right->right = NULL;
    return root;
}

// 递归求叶子结点数量
int countLeaf(TreeNode *root) {
    if (root == NULL) {
        return 0;
    }
    if (root->left == NULL && root->right == NULL) {
        return 1;
    }
    return countLeaf(root->left) + countLeaf(root->right);
}

int main() {
    TreeNode *root = createTree();
    int leafCount = countLeaf(root);
    printf("叶子结点数量：%d\n", leafCount);
    return 0;
}

在这个算法中，我们使用了递归的方法来遍历二叉树，当遍历到叶子结点时，返回1，否则返回左子树和右子树的叶子结点数量之和。最终，我们可以得到整个二叉树的叶子结点数量。