hdu 2846 Repository

字典树。字典树可以很快的算出某个前缀出现的次数，所以以每个字母作为起点，都插入到字典树中，单词的某一前缀只加一次，加一次之后标记掉，之后不再加。

由于之前没有考虑到查询的单词在字典树中没有出现，导致RE了N次。。。

#include<cstdio>
#include<cstring>
#include<cmath>
#include<string>
#include<algorithm>
using namespace std;

struct shu{ int summ, nn[27], jihao; }node[500005];
int n, i, j, k, ii, tott, zz, q;
char s[25], ls[25];

int main()
{
    while (~scanf("%d", &n))
    {
        tott = 1;
        for (i = 0; i < 500005-5; i++)
        {
            memset(node[i].nn, -1, sizeof(node[i].nn));
            node[i].summ = 0;
            node[i].jihao = -1;
        }
        for (ii = 0; ii < n; ii++)
        {
            scanf("%s", s);
            int len = strlen(s);
            for (i = 0; i < len; i++)
            {
                zz = 0;
                for (j = i; s[j]; j++)
                {
                    if (node[zz].nn[s[j] - 'a'] == -1)
                    {
                        node[zz].nn[s[j] - 'a'] = tott;
                        tott++;
                    }
                    zz = node[zz].nn[s[j] - 'a'];
                    if (node[zz].jihao != ii)
                    {
                        node[zz].summ++;
                        node[zz].jihao = ii;
                    }
                }
            }
        }
        scanf("%d", &q);
        for (ii = 0; ii < q; ii++)
        {
            int shuchu = 0;
            scanf("%s", s); zz = 0;
            for (i = 0; s[i]; i++)
            {
                zz = node[zz].nn[s[i] - 'a'];
                if (zz == -1)
                {
                    printf("%d\n", 0);
                    shuchu = 1; break;
                }
            }
            if(!shuchu) printf("%d\n", node[zz].summ);
        }
    }
    return 0;
}