KeyWords Search(AC automation)

#include <cstdio>
#include <cstring>
using namespace std;

const int num_char=26;
struct  TrieNode
{
    TrieNode *branch[num_char];
    TrieNode *fail;
    int count;//if this is the last node of the word
    TrieNode()
    {
        fail=NULL;
        count=0;
        memset(branch,NULL,sizeof(branch));
    }
} *q[500001];
int qhead,qtail;
char src[1000005];
char input[55];
void insert(const char *src,TrieNode *root)
{
    TrieNode *hp=root;
    while(*src!=0)
    {
        if(hp->branch[*src-'a']==NULL)hp->branch[*src-'a']=new TrieNode();
        hp=hp->branch[*src-'a'];
        src++;
    }
    hp->count++; //+1 stands for it's the end of a word.
}

void build_fail(TrieNode *root)
{
    int i;
    root->fail=NULL;
    q[qhead++]=root;
    while(qhead!=qtail)
    {
        TrieNode *temp=q[qtail++];
        TrieNode *p=NULL;
        for(i=0; i<26; i++)
        {
            if(temp->branch[i]!=NULL)
            {
                if(temp==root)temp->branch[i]->fail=root;
                else
                {
                    p=temp->fail;
                    while(p!=NULL)
                    {
                        if(p->branch[i]!=NULL)
                        {
                            temp->branch[i]->fail=p->branch[i];
                            break;
                        }
                        p=p->fail;
                    }
                    if(p==NULL)temp->branch[i]->fail=root;
                }
                q[qhead++]=temp->branch[i];
            }
        }
    }
}
int query(TrieNode *root)
{
    int i=0,cnt=0,index;
    TrieNode *p=root;
    while(src[i]!=0)
    {
        index=src[i]-'a';
        while(p->branch[index]==NULL&& p!=root)p=p->fail;
        p=p->branch[index];
        p=(p==NULL)?root:p;
        TrieNode *temp=p;
        while(temp!=root&&temp->count!=-1)
        {
            cnt+=temp->count;
            temp->count=-1;
            temp=temp->fail;
        }
        i++;
    }
    return cnt;
}

int main()
{
    int n;
    int t;
    scanf("%d",&t);
    while(t--)
    {
        TrieNode *root=new TrieNode();
        qtail=qhead=0;
        scanf("%d",&n);
            for(int i=0; i<n; ++i)
            {
                scanf("%s",input);
                insert(input,root);
            }
            build_fail(root);
          //  printf("input target:\n");
            scanf("%s",src);
            printf("%d\n",query(root));
    }
    return 0;
}