BZOJ 1014: [JSOI2008]火星人prefix

二次联通门 : BZOJ 1014: [JSOI2008]火星人prefix

 

 

 

 

/*
    BZOJ 1014: [JSOI2008]火星人prefix

    Splay维护Hash值
    先建树
    重点是对于插入操作，
    找到那个位置后，像链表一样更改顺序，后将这点向上一条链更新一下hash值就好
*/
#include <cstdio>
#include <iostream>
typedef long long LL;
#include <cstring>
#define Max 150000
#define BASE 257
#define rg register
int N, M; unsigned long long mi[Max];
inline void read (int &n)
{
    rg char c = getchar ();
    for (n = 0; !isdigit (c); c = getchar ());
    for (; isdigit (c); n = n * 10 + c - '0', c = getchar ());
}
struct SD
{
    SD *c[2], *f; unsigned long long h; int s; char r;
    inline void Up ()
    {
        s = c[0]->s + c[1]->s + 1;
        h = c[0]->h + r * mi[c[0]->s] + c[1]->h * mi[c[0]->s + 1];
    }
} *null, *Root = NULL, poor[Max], *Ta = poor;
char line[Max];
class SplayType
{
    private :

        void R (SD *&n)
        {
            SD *F = n->f, *G = F->f; int p = n == F->c[1];
            if ((F->c[p] = n->c[p ^ 1]) != null) F->c[p]->f = F;
            F->f = n, n->c[p ^ 1] = F;
            if ((n->f = G) != null) G->c[F == G->c[1]] = n;
            F->Up (), n->Up ();
        }
        
        void Splay (SD *&n, SD *&t)
        {
            for (SD *F; (F = n->f) != t; R (n))
                if (F->f != t) R ((F->c[1] == n) == (F->f->c[1] == F) ? F : n);
            if (t == null) Root = n;
        }
        
    public :
        
        SD *Gkth (int k)
        {
            SD *n = Root; 
            for (; k && n != null; )
            {
                if (n->c[0]->s >= k) n = n->c[0];
                else if (n->c[0]->s + 1 == k) return n;
                else k -= n->c[0]->s + 1, n = n->c[1];
            }
            return n;
        }

        SD *Build (int l, int r)
        {
            if (l > r) return null; int m = l + r >> 1;
            SD *n = ++ Ta; n->r = line[m];
            if ((n->c[0] = Build (l, m - 1)) != null) n->c[0]->f = n;
            if ((n->c[1] = Build (m + 1, r)) != null) n->c[1]->f = n;
            n->Up (); return n;
        }
        
        inline void I (int pos, char r)
        {
            SD *n = ++ Ta, *p = Gkth (pos); n->r = r;
            n->c[0] = null, n->c[1] = p->c[1], n->f = p;
            n->c[1]->f = n, p->c[1] = n, n->Up ();
            for (; p != null; p->Up (), p = p->f);
        }
        
        inline void C (int pos, char r)
        {
            SD *p = Gkth (pos), *n; p->r = r;
            for (n = p; n != null; n->Up (), n = n->f);
        }
        
        inline unsigned long long Q (int l, int r)
        {
            SD *L = Gkth (l - 1), *R = Gkth (r + 1);
            Splay (L, null), Splay (R, L); return R->c[0]->h;
        }
} S;

int Main ()
{
    scanf ("%s", line + 2); N = strlen (line + 2); read (M); rg int i, j;
    null = new SD; null->c[0] = null->c[1] = null->f = null; null->s = null->h = null->r = 0;
    for (mi[0] = i = 1; i < Max; ++ i) mi[i] = mi[i - 1] * BASE; 
    line[1] = '~', line[N + 2] = '!', Root = S.Build (1, N + 2);
    Root->f = null; int x, y, s, l, r, m; 
    for (char c; M; -- M)
    {
        for (; c = getchar (), c < 'A'; );
        if (c == 'Q')
        {
            read (x), read (y), ++ x, ++ y;
            if (S.Gkth (x)->r != S.Gkth (y)->r) { puts ("0");  continue; }
            for (s = l = 1, r = N - (x < y ? y : x) + 2; l <= r; )
            {
                m = l + r >> 1;
                if (S.Q (x, x + m - 1) == S.Q (y, y + m - 1)) l = (s = m) + 1; 
                else r = m - 1;
            }
            printf ("%d\n", s);
        }
        else 
        {
            y = c == 'R', N += y ^ 1;
            read (x), ++ x; for (; c = getchar (), c < 'a'; );
            if (y) S.C (x, c); else S.I (x, c);
        }
    }
    return 0;
}
int ZlycerQan = Main (); int main (int argc, char *argv[]) {;}