简单的数组建树+中序遍历

#include <bits/stdc++.h>
using namespace std;
struct TreeNode {
    char data;
    TreeNode* left;
    TreeNode* right;
};
TreeNode* BuileTree(int& i, char arr[]) {
    char c = arr[i];
    i++;
    if (c == '#') {
        return NULL;
    } else {
        TreeNode* pNew = new TreeNode;
        pNew->data = c;
        pNew->left = BuileTree(i, arr);
        pNew->right = BuileTree(i, arr);
        return pNew;
    }
}
void inorder(TreeNode* pRoot) {
    if (pRoot == NULL) {
        return;
    }
    inorder(pRoot->left);
    printf("%c ", pRoot->data);
    inorder(pRoot->right);
}
int main() {
    char arr[101] = {0};
    while (scanf("%s", arr) != EOF) {
        int i = 0;
        TreeNode* proot = BuileTree(i, arr);
        inorder(proot);
        printf("\n");
    }
    return 0;
}