// #pragma GCC optimize("Ofast,no-stack-protector")
// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx,avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
#define lowbit(x) ((x) & -(x))
#define ml(a, b) ((1ll * (a) * (b)) % M)
#define tml(a, b) (a) = ((1ll * (a) * (b)) % M)
#define ad(a, b) ((0ll + (a) + (b)) % M)
#define tad(a, b) (a) = ((0ll + (a) + (b)) % M)
#define mi(a, b) ((0ll + M + (a) - (b)) % M)
#define tmi(a, b) (a) = ((0ll + M + (a) - (b)) % M)
#define tmin(a, b) (a) = min((a), (b))
#define tmax(a, b) (a) = max((a), (b))
#define iter(a) (a).begin(), (a).end()
#define riter(a) (a).rbegin(), (a).rend()
#define init(a, b) memset((a), (b), sizeof(a))
#define cpy(a, b) memcpy((a), (b), sizeof(a))
#define uni(a) a.resize(unique(iter(a)) - a.begin())
#define size(x) (int)x.size()
#define pb emplace_back
#define mpr make_pair
#define ls(i) ((i) << 1)
#define rs(i) ((i) << 1 | 1)
#define INF 0x3f3f3f3f
#define NIF 0xc0c0c0c0
#define eps 1e-9
#define F first
#define S second
#define AC cin.tie(0)->sync_with_stdio(0)
using namespace std;
typedef long long llt;
typedef __int128_t lll;
typedef pair<int, int> pii;
typedef pair<double, double> pdd;
typedef pair<llt, llt> pll;
typedef pair<llt, int> pli;
typedef complex<double> cd;
// const int M = 998244353;
// random_device rm;
// mt19937 rg(rm());
// default_random_engine rg(rm());
// uniform_int_distribution<int> rd(INT_MIN, INT_MAX);
// uniform_real_distribution<double> rd(0, M_PI);
void db() { cerr << "\n"; }
template <class T, class... U>
void db(T a, U... b) { cerr << a << " ", db(b...); }
inline char gc()
{
const static int SZ = 1 << 16;
static char buf[SZ], *p1, *p2;
if (p1 == p2 && (p2 = buf + fread(p1 = buf, 1, SZ, stdin), p1 == p2))
return -1;
return *p1++;
}
void rd() {}
template <typename T, typename... U>
void rd(T &x, U &...y)
{
x = 0;
bool f = 0;
char c = gc();
while (!isdigit(c))
f ^= !(c ^ 45), c = gc();
while (isdigit(c))
x = (x << 1) + (x << 3) + (c ^ 48), c = gc();
f && (x = -x), rd(y...);
}
template <typename T>
void prt(T x)
{
if (x < 0)
putchar('-'), x = -x;
if (x > 9)
prt(x / 10);
putchar((x % 10) ^ 48);
}
const int N = 5e5 + 5;
int n, ar[N];
vector<int> pl[N];
struct TR
{
int lx, ln, rx, rn, sum;
TR operator+(const TR &rh) const
{
TR cr;
cr.sum = sum + rh.sum;
cr.lx = max(lx, sum + rh.lx);
cr.ln = min(ln, sum + rh.ln);
cr.rx = max(rh.rx, rh.sum + rx);
cr.rn = min(rh.rn, rh.sum + rn);
return cr;
}
inline void ini(int v)
{
lx = max(0, v), rx = max(0, v);
ln = min(0, v), rn = min(0, v);
sum = v;
}
} tr[N << 2], vv;
int ql, qr, qv;
#define L l, m, ls(id)
#define R m + 1, r, rs(id)
#define pul() tr[id] = tr[ls(id)] + tr[rs(id)]
void blt(int l, int r, int id)
{
if (l == r)
{
tr[id].ini(1);
return;
}
int m = (l + r) >> 1;
blt(L), blt(R), pul();
}
void qy(int l, int r, int id)
{
if (ql <= l && r <= qr)
{
vv = vv + tr[id];
return;
}
int m = (l + r) >> 1;
if (ql <= m)
qy(L);
if (qr > m)
qy(R);
}
void cg(int l, int r, int id)
{
if (ql <= l && r <= qr)
{
tr[id].ini(qv);
return;
}
int m = (l + r) >> 1;
if (ql <= m)
cg(L);
if (qr > m)
cg(R);
pul();
}
int sequence(int _n, vector<int> aa)
{
n = _n;
for (int i = 1; i <= n; i++)
pl[ar[i] = aa[i - 1]].pb(i);
int ans = 1;
blt(1, n, 1);
vector<int> sum, lx, rx, ln, rn;
for (int p = 1; p <= n; p++)
{
int len = size(pl[p]);
if (len > ans)
{
sum.resize(len);
lx.resize(len);
rx.resize(len);
ln.resize(len);
rn.resize(len);
for (int i = 0; i < len; i++)
{
vv.ini(0);
ql = 1, qr = pl[p][i];
qy(1, n, 1);
sum[i] = vv.sum - i - 1;
lx[i] = vv.rx - 1;
vv.ini(0);
ql = pl[p][i], qr = n;
qy(1, n, 1);
rx[i] = vv.lx - 1;
}
for (int i : pl[p])
ql = qr = i, qv = -1, cg(1, n, 1);
for (int i = 0; i < len; i++)
{
vv.ini(0);
ql = 1, qr = pl[p][i];
qy(1, n, 1);
ln[i] = vv.rn + 1;
vv.ini(0);
ql = pl[p][i], qr = n;
qy(1, n, 1);
rn[i] = vv.ln + 1;
}
auto ck = [&](int lm) -> bool
{
for (int r = lm - 1, l = 0; r < len; r++, l++)
{
int cv = sum[r] - sum[l];
if (abs(cv) <= lm)
return 1;
if (cv < 0)
{
if (cv + lm + lx[l] + rx[r] >= 0)
return 1;
}
else
{
if (cv - lm + ln[l] + rn[r] <= 0)
return 1;
}
}
return 0;
};
int l = ans + 1, r = len;
while (l <= r)
{
int m = (l + r) >> 1;
if (ck(m))
l = m + 1, tmax(ans, m); // ans = m
else
r = m - 1;
}
}
else
for (int i : pl[p])
ql = qr = i, qv = -1, cg(1, n, 1);
}
return ans;
}
signed main()
{
int nn;
rd(nn);
vector<int> aa(nn);
for (int i = 0; i < nn; i++)
rd(aa[i]);
prt(sequence(nn, aa)), putchar('\n');
}
Compilation message
/usr/bin/ld: /tmp/ccUHLwC8.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cc9oU994.o:sequence.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
