题解 | 二叉树遍历

#include <stdio.h>

struct TreeNode {
    char data;
    TreeNode* left;
    TreeNode* right;
};
TreeNode* RecursiveBuildTree(int &index, char str[]) {
    char c = str[index];
    index++;
    if (c == '#') {
        return NULL;
    } else {
        TreeNode* pNew = new TreeNode();
        pNew->data = c;
        pNew->left = RecursiveBuildTree(index, str);
        pNew->right = RecursiveBuildTree(index, str);
        return pNew;
    }
}

void InOrder(TreeNode* root) {
    if (root == NULL) {
        return;
    }
    InOrder(root->left);
    printf("%c ", root->data);
    InOrder(root->right);
}

int main() {
    char str[100];
    while (scanf("%s", str) != EOF) {
        int index = 0;
        TreeNode* root = RecursiveBuildTree(index, str);
        InOrder(root);
        printf("\n");
    }

}