【动态树】[BZOJ2002] Bounce 弹飞绵羊

实际上就是动态树的模版加上一个维护每一条链的size这样就可以吧一次弹射看成一条路径，然后统计这个路径上的size实际上就是经过了多少个节点然后没什么了。。

#include <bits/stdc++.h>using namespace std;const int MAXN = 200000;int ch[MAXN+10][2], Fa[MAXN+10];int que[MAXN+10], sz[MAXN+10];bool rev[MAXN+10];bool isroot(int u){return ch[Fa[u]][0] != u && ch[Fa[u]][1] != u;}void Rotate(int u){    int x = Fa[u], y = Fa[x];    bool md = ch[x][1] == u;    Fa[u] = y;    if(!isroot(x)) ch[y][ch[y][1] == x] = u;    ch[x][md] = ch[u][!md]; Fa[ch[u][!md]] = x;    ch[u][!md] = x; Fa[x] = u;    sz[x] = sz[ch[x][0]] + sz[ch[x][1]] + 1;}void push_down(int u){    if(rev[u]){        rev[u] ^= 1; rev[ch[u][0]] ^= 1; rev[ch[u][1]] ^= 1;        swap(ch[u][0], ch[u][1]);    }}void Splay(int u){    int now = u;    que[0] = 1; que[1] = now;    while(!isroot(now)){        que[++que[0]] = Fa[now];        now = Fa[now];    }    for(;que[0];que[0]--) push_down(que[que[0]]);    while(!isroot(u)){        int x = Fa[u], y = Fa[x];        if(!isroot(x)){            if((ch[x][0] == u) ^ (ch[y][0] == x)) Rotate(u);            else Rotate(x);        }        Rotate(u);    }    sz[u] = sz[ch[u][0]] + sz[ch[u][1]] + 1;}void access(int u){    int up = 0;    while(u != 0){        Splay(u);        ch[u][1] = up;        up = u; u = Fa[u];    }}void root(int u){    access(u);    Splay(u);    rev[u] ^= 1;}void Link(int x, int y){    root(x);    Fa[x] = y;    Splay(x);}void Cut(int x, int y){    root(x);    access(y);    Splay(y);    ch[y][0] = Fa[x] = 0;}/*bool Query(int x, int y){    access(x); Splay(x);    int u = x;    while(ch[u][0]) u = ch[u][0];    access(y); Splay(y);    int u1 = y;    while(ch[u1][0]) u1 = ch[u1][0];    return u == u1;}*/int Jp[MAXN+10];int main(){    int n, m, a, b;    scanf("%d", &n);    for(int i=1;i<=n;i++){        scanf("%d", &a);        Jp[i] = min(i+a, n+1);        Link(Jp[i], i);    }    int ord;    scanf("%d", &m);    for(int i=0;i<m;i++){        scanf("%d", &ord);        if(ord == 1){            scanf("%d", &a);            root(n+1);            access(a+1);            Splay(a+1);            printf("%d\n", sz[ch[a+1][0]]);        }        else{            scanf("%d %d", &a, &b);            Cut(a+1, Jp[a+1]);            Jp[a+1] = a + 1 + b;            if(a + b + 1 > n) Jp[a+1] = n+1;            Link(Jp[a+1], a+1);        }    }    return 0;}