统计难题

 http://acm.hdu.edu.cn/showproblem.php?pid=1251

总结：字典树；

/*#include 
#include 
#include 
#include 
#include 
#include */
#include
using namespace std;

#define sfi(i) scanf("%d",&i)
#define sfl(i) scanf("%lld",&i)
#define sfs(i) scanf("%s",(i))
#define pri(i) printf("%d\n",i)
#define sff(i) scanf("%lf",&i)
#define ll long long
#define ull unsigned long long
#define mem(x,y) memset(x,y,sizeof(x))
#define INF 0x3f3f3f3f
#define eps 1e-10
#define PI acos(-1.0)
#define lowbit(x) ((x)&(-x))
#define zero(x) (((x)>0?(x):-(x))
#include
#include 
using namespace __gnu_pbds;
*/

//gp_hash_tablemp2;
//__gnu_pbds::priority_queueq;//因为放置和std重复，故需要带上命名空间
//__gnu_pbds::priority_queue,pairing_heap_tag> pq;//最快
//----------------------------------------------------------



//----------------------------------------------------------
const int BufferSize = 1 << 16;
char buffer[BufferSize], *_head, *_tail;
inline char Getchar() {
    if (_head == _tail) {
        int l = fread(buffer, 1, BufferSize, stdin);
        _tail = (_head = buffer) + l;
    }
    return *_head++;
 }
inline int read() {
    int x = 0, f = 1;char c = Getchar();
    for (;!isdigit(c);c = Getchar()) if (c == '-') f = -1;
    for (;isdigit(c);c = Getchar()) x = x * 10 + c - '0';
    return x * f;
 }
//----------------------------------------------------------




const int maxn=2e6+9;
const int mod=1e9+7;

int tree[maxn][39],sum[maxn];
bool flagg[maxn];
int tot;
void insert_str(char *str)
{
    int len=strlen(str);
    int rt=0;
    for(int i=0;i