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| #include <cstdio>
const int N = 1e5 + 10, inf = 1e7 + 1;
struct Node
{
int p, sz, s[2];
int v, cnt;
} tr[N];
int m, rt, idx;
void pushup(int x)
{
tr[x].sz = tr[tr[x].s[0]].sz + tr[tr[x].s[1]].sz + tr[x].cnt;
}
void rotate(int x)
{
int y = tr[x].p, z = tr[y].p;
int k = tr[y].s[1] == x;
tr[z].s[tr[z].s[1] == y] = x;
tr[x].p = z;
tr[y].s[k] = tr[x].s[k ^ 1];
tr[tr[x].s[k ^ 1]].p = y;
tr[x].s[k ^ 1] = y;
tr[y].p = x;
pushup(y);
pushup(x);
}
void splay(int x, int k)
{
while (tr[x].p != k)
{
int y = tr[x].p, z = tr[y].p;
if (z != k)
if ((tr[y].s[1] == x) ^ (tr[z].s[1] == y))
rotate(x);
else
rotate(y);
rotate(x);
}
if (!k)
rt = x;
}
void insert(int x)
{
int u = rt, p;
while (u)
{
if (tr[u].v == x)
{
tr[u].cnt++;
tr[u].sz++;
splay(u, 0);
return;
}
p = u;
u = tr[u].s[x > tr[u].v];
}
u = ++idx;
if (p)
tr[p].s[x > tr[p].v] = u;
tr[u].v = x;
tr[u].sz = 1;
tr[u].p = p;
tr[u].cnt = 1;
splay(u, 0);
}
void init()
{
rt = ++idx;
tr[rt].p = 0;
tr[rt].sz = 1;
tr[rt].cnt = 1;
tr[rt].v = inf;
insert(-inf);
}
int pre(int x)
{
int u = rt, res, v = rt;
while (u)
{
v = u;
if (tr[u].v < x)
{
res = u;
u = tr[u].s[1];
}
else
u = tr[u].s[0];
}
splay(v, 0);
return res;
}
int nxt(int x)
{
int u = rt, res, v = rt;
while (u)
{
v = u;
if (tr[u].v > x)
{
res = u;
u = tr[u].s[0];
}
else
u = tr[u].s[1];
}
splay(v, 0);
return res;
}
void remove(int x)
{
int l = pre(x), r = nxt(x);
splay(l, 0);
splay(r, l);
tr[tr[r].s[0]].cnt--;
tr[tr[r].s[0]].sz--;
if (!tr[tr[r].s[0]].cnt)
{
tr[tr[r].s[0]].p = 0;
tr[r].s[0] = 0;
}
splay(r, 0);
}
int num(int x)
{
int u = rt;
while (u)
{
if (tr[tr[u].s[0]].sz >= x)
u = tr[u].s[0];
else if (x <= tr[tr[u].s[0]].sz + tr[u].cnt && x >= tr[tr[u].s[0]].sz + 1)
{
splay(u, 0);
return u;
}
else
{
x -= tr[tr[u].s[0]].sz + tr[u].cnt;
u = tr[u].s[1];
}
}
}
int main()
{
init();
scanf("%d", &m);
for (int op, x; m; m--)
{
scanf("%d%d", &op, &x);
if (op == 1)
insert(x);
else if (op == 2)
remove(x);
else if (op == 3)
{
splay(pre(x), 0);
printf("%d\n", tr[tr[rt].s[0]].sz + tr[rt].cnt);
}
else if (op == 4)
printf("%d\n", tr[num(x + 1)].v);
else if (op == 5)
printf("%d\n", tr[pre(x)].v);
else if (op == 6)
printf("%d\n", tr[nxt(x)].v);
}
return 0;
}
|