자료구조_c언어_tree

#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
 
typedef struct treeNode {
    char data;
    struct treeNode *left;
    struct treeNode *right;
}treeNode;
 
treeNode* makeRootNode(char data, treeNode *leftNode, treeNode *rightNode) {
    treeNode *root = (treeNode*)malloc(sizeof(treeNode));
    root->data = data;
    root->left = leftNode;
    root->right = rightNode;
    return root;
}
 
void preorder(treeNode *root) {
    if (root) {
        printf("%c", root->data);
        preorder(root->left);
        preorder(root->right);
    }
}
 
void inorder(treeNode *root) {
    if (root) {
        inorder(root->left);
        printf("%c", root->data);
        inorder(root->right);
    }
}
 
void postorder(treeNode *root) {
    if (root) {
        postorder(root->left);
        postorder(root->right);
        printf("%c", root->data);
    }
}
 
int main() {
    treeNode *n7 = makeRootNode('D', NULL, NULL);
    treeNode *n6 = makeRootNode('C', NULL, NULL);
    treeNode *n5 = makeRootNode('B', NULL, NULL);
    treeNode *n4 = makeRootNode('A', NULL, NULL);
 
    treeNode *n3 = makeRootNode('/', n6, n7);
    treeNode *n2 = makeRootNode('*', n4, n5);
    treeNode *n1 = makeRootNode('-', n2, n3);
 
    printf("\n preorder:");
    preorder(n1);
 
    printf("\n inorder:");
    inorder(n1);
 
    printf("\n postorder:");
    postorder(n1);
 
    getchar();
 
    return 0;
}