题解 | #二叉树遍历#

#include<cstdio>
#include<string>
using namespace std;
struct TreeNode {
    char data;
    TreeNode* LChild;
    TreeNode* RChild;
};
TreeNode* RecursiveBuildTree(int& i, string str) {
    //返回本棵子树根节点地址；
    char c = str[i];
    ++i;
    if (c == '#') {
        return NULL;
    } else {
        TreeNode* pa = new TreeNode;
        pa->data = c;
        pa->LChild = RecursiveBuildTree(i, str);
        pa->RChild = RecursiveBuildTree(i, str);
        return  pa ;
    }

}
void MidOrder(TreeNode* root) {
    if (root == NULL) {
        return;
    }
    MidOrder(root->LChild);
    printf("%c ", root->data);
    MidOrder(root->RChild);
}
int main() {
    char arr[100];
    while (scanf("%s", arr) != EOF) {
        string str = arr;
        int i = 0 ;
        TreeNode* root = RecursiveBuildTree(i, str);
        MidOrder(root);
        printf("\n");
    }

}