BZOJ2002弹飞绵羊

动态树LCT模板题

#include<cstdio>
#include<cctype>
#include<algorithm>
using namespace std;
inline int read()
{
    int x = 0, flag = 1;
    char c;
    while(! isgraph(c = getchar()))
        if(c == '-')
            flag *= - 1;
    while(isgraph(c))
        x = x * 10 + c - '0', c = getchar();
    return x * flag;
}
inline void println(int x)
{
    if(x < 0)
        putchar('-');
    if(x == 0)
        putchar('0');
    int top = 0, ans[10 + (1 << 4)];
    while(x)
        ans[top ++] = x % 10, x /= 10;
    for(; top; top --)
        putchar(ans[top - 1] + '0');
    putchar('\n');
}
const int MAXN = (int)2e5 + (1 << 5);
struct node
{
    int isroot, ch[2], fa, size;
}T[MAXN];
void update(int u)
{
    T[u].size = ((T[u].ch[0] == - 1) ? 0 : T[T[u].ch[0]].size) 
        + ((T[u].ch[1] == - 1) ? 0 : T[T[u].ch[1]].size) + 1;
}
inline int get_rela(int u)
{
    return u == T[T[u].fa].ch[1];
}
void rotate(int u)
{
    int fa = T[u].fa, fafa = T[T[u].fa].fa, rela = get_rela(u);
    T[T[u].ch[rela ^ 1]].fa = fa;
    T[fa].ch[rela] = T[u].ch[rela ^ 1];
    T[u].ch[rela ^ 1] = fa;
    T[fa].fa = u;
    T[u].fa = fafa;
    if(T[fa].isroot)
        T[fa].isroot = 0, T[u].isroot = 1;
    else
        T[fafa].ch[T[fafa].ch[1] == fa] = u;
    update(fa), update(u);
}
void splay(int u)
{
    while(1)
    {
        if(T[u].isroot)
            break;
        if(! T[T[u].fa].isroot)
            rotate((get_rela(u) == get_rela(T[u].fa)) ? T[u].fa : u);
        rotate(u);
    }
}
void access(int u)
{
    splay(u);
    while(T[u].fa != - 1)
    {
        int fa = T[u].fa;
        splay(fa);
        if(T[fa].ch[1] != - 1)
            T[T[fa].ch[1]].isroot = 1;
        T[u].isroot = 0;
        T[fa].ch[1] = u;
        update(fa);
        splay(u);
    }
}
int main()
{
    #ifndef ONLINE_JUDGE
    freopen("BZOJ2002.in", "r", stdin);
    freopen("BZOJ2002.out", "w", stdout);
    #endif
    int n = read();
    T[n].fa = - 1;
    for(int i = 0; i < n; i ++)
        T[i].fa = min(read() + i, n);
    for(int i = 0; i <= n; i ++)
        T[i].size = 1, T[i].isroot = 1, T[i].ch[0] = T[i].ch[1] = - 1;
    int m = read();
    for(int i = 0; i < m; i ++)
    {
        int opt = read();
        if(opt == 1)
        {
            int u = read();
            access(u);
            println(T[T[u].ch[0]].size);    //这里要稍微注意一下 
            continue;
        }
        int u = read();
        splay(u);
        T[T[u].ch[0]].fa = T[u].fa;
        T[T[u].ch[0]].isroot = 1;
        T[u].ch[0] = - 1;
        T[u].size = ((T[u].ch[1] == - 1) ? 0 : T[T[u].ch[1]].size) + 1;
        T[u].fa = min(n, read() + u);
    }
}