// author : anhtun_hi , nqg
// 25-26.12.2024
#include <bits/stdc++.h>
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define reset(h, v) memset(h, v, sizeof h)
#define Forv(i, a) for(auto& i : a)
#define For(i, a, b) for(int i = a; i <= b; ++i)
#define Ford(i, a, b) for(int i = a; i >= b; --i)
#define c_bit(i) __builtin_popcountll(i)
#define Bit(mask, i) ((mask >> i) & 1LL)
#define onbit(mask, i) ((mask) bitor (1LL << i))
#define offbit(mask, i) ((mask) &~ (1LL << i))
#define Log2(x) (63 - __builtin_clzll(x))
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
using namespace std;
using ll = long long;
using ii = pair<ll, ll>;
using db = long double;
using ull = unsigned long long;
namespace std {
template <typename T, int D>
struct _vector : public vector <_vector <T, D - 1>> {
static_assert(D >= 1, "Dimension must be positive!");
template <typename... Args>
_vector(int n = 0, Args... args) : vector <_vector <T, D - 1>> (n, _vector <T, D - 1> (args...)) {}
};
template <typename T> struct _vector <T, 1> : public vector <T> {
_vector(int n = 0, const T& val = T()) : vector <T> (n, val) {}
};
template <class A, class B> bool minimize(A &a, B b){return a > b ? a = b, true : false;}
template <class A, class B> bool maximize(A &a, B b){return a < b ? a = b, true : false;}
}
const int dx[] = {0, 0, +1, -1}, dy[] = {-1, +1, 0, 0}, LOG = 20, base = 311, inf = 1e9 + 5;
const int MAXN = 2e5 + 5;
const ll mod = 1e9 + 7;
const ll oo = 1e18;
//#define int long long
int n, a[MAXN], b[MAXN], Block;
vector<int> List[MAXN];
struct Fenwick{
int bit[MAXN * 2];
void update(int u, int val){
u += 2e5+1;
while(u <= 4e5+5) bit[u] += val, u += u &- u;
}
ll get(int u){
u += 2e5+1;
ll res = 0;
while (u) res += bit[u], u -= u &- u;
return res;
}
} T;
int cnt[MAXN], f[MAXN];
void Solve() {
cin >> n; Block = 1000;
vector<int> compress;
For(i, 1, n) cin >> a[i], compress.push_back(a[i]);
sort(all(compress)), compress.resize(unique(all(compress)) - compress.begin());
For(i, 1, n) {
a[i] = lower_bound(all(compress), a[i]) - compress.begin() + 1;
List[a[i]].push_back(i);
}
ll ans = 0;
For(i, 1, n){
int mx = 0;
for (int j = i; j <= min(n, i + 2 * Block - 1); ++j){
if (List[a[j]].size() <= Block) ++cnt[a[j]], maximize(mx, cnt[a[j]]);
if (mx * 2 > (j - i + 1)) ++ans;//cerr << i << ' ' << j << '\n';
}
for (int j = i; j <= min(n, i + 2 * Block - 1); ++j){
if (List[a[j]].size() <= Block) --cnt[a[j]];
}
}
vector<int> vec;
For(i, 1, n) if (List[i].size() > Block) vec.push_back(i);
Forv(u, vec){
For(i, 1, n) {
if(a[i] == u) b[i] = 1;
else b[i] = -1;
}
For(i, 1, n) f[i] = f[i - 1] + b[i];//cerr << f[i] << ' '; cerr << '\n';
For(i, 0, n) ans += T.get(f[i] - 1), T.update(f[i], 1);
For(i, 0, n) T.update(f[i], -1);
}
cout << ans << '\n';
}
signed main() {
cin.tie(0) -> sync_with_stdio(0);
if(fopen("a.inp", "r")) {
freopen("a.inp", "r", stdin);
freopen("a.out", "w", stdout);
}
int t = 1;
// cin >> t;
while(t --) Solve();
return 0;
}
컴파일 시 표준 에러 (stderr) 메시지
Main.cpp: In function 'int main()':
Main.cpp:101:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
101 | freopen("a.inp", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
Main.cpp:102:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
102 | freopen("a.out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |