《 字典树模板_递归 》

#include <iostream>
#include <cstdlib>
#include <cstdio>


using namespace std;

struct tree
{
    int val;
    tree *next[26];
};
tree *head;

void Insert(tree *p, char *ch, int pp)
{
    if (ch[pp] == '')
    {
        p->val++;
        return;
    }
    if (p->next[ch[pp] - 'a'] == NULL)
    {
        tree *q = (tree *)malloc(sizeof(tree));
        q->val = 0;
        for (int i = 0; i < 26; i++)
        {

            q->next[i] = NULL;
        }
        p->next[ch[pp] - 'a'] = q;

    }
    Insert(p->next[ch[pp] - 'a'], ch, pp+1);
}

int Query(tree *p, char *ch, int pp)
{
    if(ch[pp] == '')
        return p->val;
    if(p->next[ch[pp] - 'a'] == NULL)
        return 0;
    else
        Query(p->next[ch[pp] - 'a'], ch, pp+1);
}

int Query(char *ch)
{
    return Query(head, ch, 0);
}


int main()
{

    char a[250], b[250];
    while(scanf("%s%s",a,b) != EOF)
    {
        head = (tree *)malloc(sizeof(tree));
        head->val = 0;
        for(int i = 0; i < 26; i++)
        {
            head->next[i] = NULL;
        }
        Insert(head,a,0);
        cout<<Query(b)<<endl;
    }

}