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| #include<cmath>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define sqz main
#define ll long long
#define rep(i, a, b) for (int i = (a); i <= (b); i++)
#define per(i, a, b) for (int i = (a); i >= (b); i--)
#define Rep(i, a, b) for (int i = (a); i < (b); i++)
#define travel(i, u) for (int i = head[u]; ~i; i = edge[i].next)
const ll INF = 1e9, Mo = 998244353;
const int N = 300000;
const double eps = 1e-6;
namespace slow_IO
{
ll read()
{
ll x = 0; int zf = 1; char ch = getchar();
while (ch != '-' && (ch < '0' || ch > '9')) ch = getchar();
if (ch == '-') zf = -1, ch = getchar();
while (ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
return x * zf;
}
void write(ll y)
{
if (y < 0) putchar('-'), y = -y;
if (y > 9) write(y / 10);
putchar(y % 10 + '0');
}
}
using namespace slow_IO;
int X[N + 5];
struct LinkCutTree
{
int Fa[N + 5], rev[N + 5], Son[N + 5][2], Size[N + 5], Stack[N + 5], top;
inline void up(int u)
{
Size[u] = Size[Son[u][0]] + Size[Son[u][1]] + 1;
}
inline void down(int u)
{
if (!rev[u]) return;
rev[Son[u][0]] ^= 1, rev[Son[u][1]] ^= 1, rev[u] ^= 1;
swap(Son[u][0], Son[u][1]);
}
inline int isroot(int u)
{
return (Son[Fa[u]][0] != u && Son[Fa[u]][1] != u);
}
inline void Rotate(int x)
{
int y = Fa[x], z = Fa[y];
int l = Son[y][1] == x, r = l ^ 1;
if (!isroot(y)) Son[z][Son[z][1] == y] = x;
Son[y][l] = Son[x][r], Fa[Son[x][r]] = y;
Son[x][r] = y, Fa[y] = x, Fa[x] = z;
up(y); up(x);
}
inline void Splay(int x)
{
Stack[top = 1] = x;
for (int y = x; !isroot(y); y = Fa[y]) Stack[++top] = Fa[y];
per(i, top, 1) down(Stack[i]);
while (!isroot(x))
{
int y = Fa[x], z = Fa[y];
if (!isroot(y))
{
if ((Son[y][1] == x) ^ (Son[z][1] == y)) Rotate(x);
else Rotate(y);
}
Rotate(x);
}
}
inline void Access(int u)
{
for (int last = 0; u; last = u, u = Fa[u])
Splay(u), Son[u][1] = last, up(u);
}
inline void Make_Root(int u)
{
Access(u); Splay(u); rev[u] ^= 1;
}
inline int Find_Root(int u)
{
Access(u), Splay(u);
while (Son[u][0]) u = Son[u][0];
return u;
}
inline void Split(int x, int y)
{
Make_Root(x), Access(y), Splay(y);
}
inline void Link(int x, int y)
{
Make_Root(x);
if (Find_Root(y) == x) return;
Fa[x] = y;
}
inline void Cut(int x, int y)
{
Make_Root(x);
if (Find_Root(y) != x || Fa[x] != y || Son[x][1]) return;
Fa[x] = Son[y][0] = 0;
}
}LCT;
int sqz()
{
int n = read();
rep(i, 1, n) X[i] = read();
rep(i, 1, n) LCT.Link(i, i + X[i] <= n ? i + X[i] : n + 1);
int q = read();
while (q--)
{
int op = read();
if (op == 1)
{
int x = read() + 1;
LCT.Split(x, n + 1);
printf("%d\n", LCT.Size[n + 1] - 1);
}
else
{
int x = read() + 1, y = read();
LCT.Cut(x, x + X[x] <= n ? x + X[x] : n + 1);
LCT.Link(x, x + y <= n ? x + y : n + 1); X[x] = y;
}
}
}
|
