无法让主要与二叉树实现一起工作

Question

我已经上下检查过，我的二叉树的实现似乎是正确的，并且适用于用/* */注释掉的实现，但对于我的 int main while 循环，插入不会在根(第一个值(插入和存储值并检查它是否确实将值存储在函数中，但第二次调用再次说其空。你能解释一下我的主文件与二叉树有什么问题吗？我将不胜感激！

-> http://ideone.com/w9Aa1w(我的函数嵌入与注释代码工作(

using namespace std;
int choice = 6;
string value;
int main(void)
 {
  //not working implentation
   while(choice != 5){
  //binary tree test
    cout << "Enter 1 to insert " << endl;
    cout << "Enter 2 to search " << endl;
    cout << "Enter 3 to display tree " << endl;
    cout << "Enter 4 to delete tree " << endl;
    cout << "Enter 5 to exit.. " << endl;
       Tree<std::string> B;
    cout << "Your choice -> : " << endl;
    cin >> choice;
 if(choice == 1)
 {
        cout << "Enter value to insert: ";
         cin >> value;
        cout << endl;
        cout << "Inserting new node! " << endl;
        B.insertTree(value);
 }
 if(choice == 2)
 {   
        cout << "Enter value to search: ";
         cin >> value;
        cout << endl;
        cout << "Search for value..." << endl;
        B.searchTree();
  if(choice == 3)
  {    
       cout << "Displaying tree data" << endl;
       B.displayTree();
  }
  if(choice == 4)
  {
       cout << "Deleting tree data" << endl;
       B.deleteTree();     
  }                    
   if(choice == 5)
   cout << "exiting..." << endl;          
  }
    /* //Working part of program seperate function**********
Tree<std::string> tree;
    tree.insertTree(std::string("Hello"));
    tree.insertTree(std::string("World"));
    Tree<std::string>::node* node = tree.searchTree("World");
    cout << node << endl;
     return 0; */

Answer 1

你的树B在循环的每次迭代中都会超出范围。

while(choice != 5){
   //...
   Tree<std::string> B;
   //...
}

您需要移动它，使其在运行期间保持在范围内：

Tree<std::string> B;
while(choice != 5){
   //...
   //...
}