题解 | #二叉树遍历#

#include <iostream>
using namespace std;

struct TreeNode {
    char val;
    TreeNode* left;
    TreeNode* right;
};

int i = 0;
void create(string& s, TreeNode*& node) {
    if (i >= s.size() || s[i] == '#') {
        node = nullptr;
        i++; 
        return;
    } else {
        node = new TreeNode;
        node->val = s[i++];
        create(s, node->left);
        create(s, node->right);
    }
}

void infixOrder(TreeNode* node)
{
	if(node == nullptr) return;
	infixOrder(node->left);
	cout << node->val << " ";
	infixOrder(node->right);

}

int main(void) {
    string s;
    cin >> s;
    TreeNode* root = nullptr;
    create(s, root);
	infixOrder(root);
    return 0;
}