关于含有递归算法的C语言代码流程图怎么画

Question

画出下面代码的程序流程图

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

// Binary tree node structure
struct TreeNode {
    char data;
    struct TreeNode* left;
    struct TreeNode* right;
};

// Create a new node
struct TreeNode* createNode(char data) {
    struct TreeNode* newNode = (struct TreeNode*)malloc(sizeof(struct TreeNode));
    if (newNode == NULL) {
        printf("Memory allocation failed!\n");
        exit(1);
    }
    newNode->data = data;
    newNode->left = NULL;
    newNode->right = NULL;
    return newNode;
}

// Build the binary tree
struct TreeNode* buildTree() {
    char data;
    printf("Enter node value (or . for NULL): ");
    scanf(" %c", &data);

    if (data == '.')
        return NULL;

    struct TreeNode* root = createNode(data);
    printf("Enter left child of %c:\n", data);
    root->left = buildTree();
    printf("Enter right child of %c:\n", data);
    root->right = buildTree();

    return root;
}

// Perform post-order traversal of the binary tree
void postOrderTraversal(struct TreeNode* root) {
    if (root == NULL)
        return;

    postOrderTraversal(root->left);
    postOrderTraversal(root->right);
    printf("%c ", root->data); 
}

// Find the path to a specified node
int findNodePath(struct TreeNode* root, char target, char path[], int level) {
    int i;
    if (root == NULL)
        return 0;

    // Add the current node to the path
    path[level] = root->data;

    // Found the target node
    if (root->data == target) {
        // Print the path
        printf("Path to node %c: ", target);
        for ( i = 0; i <= level; i++) {
            printf("%c ", path[i]);
        }
        printf("\n");
        return 1;
    }

    // Search for the target node in the left or right subtree
    if (findNodePath(root->left, target, path, level + 1) || findNodePath(root->right, target, path, level + 1))
        return 1;

    // If the current node is not in the path, remove it
    path[level] = '\0';
    return 0;
}

int main() {
    // Build the binary tree
    printf("Build the binary tree:\n");
    struct TreeNode* root = buildTree();

    // Perform post-order traversal of the binary tree
    printf("Post-order Traversal: ");
    postOrderTraversal(root);
    printf("\n");

    // Find the path to a specified node
    char path[100];  // Assume the path does not exceed 100 nodes
    char target;
    printf("Enter the target node value: ");
    scanf(" %c", &target);
    findNodePath(root, target, path, 0);

    return 0;
}

Answer 1

一样地画，递归就是调用函数而已。
当然，递归算法用流程图来表示是否直观，就见仁见智了。