c++输出二叉树叶子结点并输出叶子结点到根结点的路径长度

#include<iostream>
#include <string>

using namespace std;
//结构体
typedef struct node
{
     char data;
     struct node *lchild,*rchild;
}binary_tree,*tree;

//构造一棵树，以字符0作为空
void creat_tree(tree &t)
{
     char ch;
     cin>>ch;
     if(ch == '0')
     {
        t=NULL;
     }
     else
     {
        t = new binary_tree;
        if(!t) exit(0); //如果没成功申请空间 则退出
        t->data=ch;
        creat_tree(t->lchild);
        creat_tree(t->rchild);
     }
}
//打印路径
bool printPath(tree &t, char data)
{
     if (t == NULL)
         return false;

     if (t->data == data || printPath(t->lchild,data) || printPath(t->rchild,data))
     {
          cout<<t->data;   //路径上的结点标识打印出来
          return true;
     }

     return false;
}
//输出路径长度
void printLeavesDepth(tree &t, size_t depth = 0)
{
  if (t == NULL) return;
  if (t->lchild == NULL && t->rchild == NULL)
  {
    cout<<t->data<<": "<<depth<<endl;
  }
  else
  {
    printLeavesDepth(t->lchild, depth+1);
    printLeavesDepth(t->rchild, depth+1);
  }
}
//输出叶子结点值
void DispLeaf(tree &t)
{
    if(t)
    {
        if(t->lchild==NULL&&t->rchild==NULL)
        {
            cout<<t->data<<"  ";
        }
        DispLeaf(t->lchild);
        DispLeaf(t->rchild);
    }
}

int main()
{
     tree t;
     cout<<"请输入二叉树节点：（例如输入:ab00c00）";
     creat_tree(t);
     cout<<"输出叶子结点"<<endl;
     DispLeaf(t);
     cout<<endl;
     cout<<"各个叶子结点到根结点的路径长度"<<endl;
     printLeavesDepth(t,0);
     system("pause");
     return 0;
}