统计难题

#include <iostream>
#include <cstdlib>
#include <string>

using namespace std;
struct DTree
{
    int c;
    DTree *next[26];
};
DTree *CreatDTree()
{
    DTree *head = new DTree;
    head -> c = 0;
    for(int i = 0;i < 26;i ++)
    {
        head -> next[i] = NULL;
    }
    return head;
}
DTree *SetDTree(DTree *head,string a)
{
    DTree *h = head;
    for(int i = 0;i < a.size();i ++)
    {
        if(head -> next[a[i] - ‘a‘] == NULL)
        {
            head -> next[a[i] - ‘a‘] = CreatDTree();
        }
        head = head -> next[a[i] - ‘a‘];
        head -> c ++;
    }
    return h;
}
int Count(DTree *head,string b)
{
    for(int i = 0;i < b.size();i ++)
    {
        head = head -> next[b[i] - ‘a‘];
        if(head == NULL) return 0;
    }
    return head -> c;
}
int main()
{
    string a,b;
    DTree *head = CreatDTree();
    while(getline(cin,a)&&a.size())
    {
        head = SetDTree(head,a);
    }
    while(cin>>b)
    {
        cout<<Count(head,b)<<endl;
    }
}