# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
795731 | NguyenKhang | Izbori (COCI22_izbori) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
//#pragma GCC optimize("Ofast,unroll-loops")
//#pragma GCC target("bmi,bmi2,lzcnt,popcnt")
//#pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
//#pragma expected_value
//#pragma isolated_call
//#pragma disjoint
#include<bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//using namespace __gnu_pbds;
using namespace std;
#define int long long
//#define double long double
#define Fi first
#define Se second
#define Rep(i,a,b) for (int i=a;i<=b;++i)
#define Repu(i,b,a) for (int i=b;i>=a;--i)
#define pb push_back
#define ms(a,i) memset(a,i,sizeof(a))
#define sz size()
#define mp make_pair
#define endl '\n'
#define sef setprecision(6)<<fixed
#define cer cout<<"cak"<<endl;
typedef pair<int,int> ii;
typedef vector<int> vi;
typedef vector<double> va;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<va> vva;
//const double EPS=1e-9;
const double PI=acos(-1);
const long long oo=1e18;
const int MN=2e5+5;
const int mod=1e9+7;
using cd=complex<double>;
//typedef tree<int,null_type,less<int>,rb_tree_tag, tree_order_statistics_node_update> index_set;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int cunt = 400;
int n;
int a[MN];
vi s[MN];
int cnt;
int ans = 0;
int type[MN];
void compress() {
vii v; v.pb(mp(0,0));
Rep(i,1,n) v.pb(mp(a[i],i));
sort(v.begin(),v.end());
Rep(i,1,n) {
if(v[i].Fi != v[i-1].Fi) ++cnt;
a[v[i].Se] = cnt;
s[cnt].pb(v[i].Se);
}
}
void light() {
Rep(i,1,n) {
int mx = 0;
Rep(j,i,min(i+cunt,n)) {
int color = a[j];
if(type[color] == 0) continue;
int temp = lower_bound(s[color].begin(), s[color].end(), j) - lower_bound(s[color].begin(), s[color].end(), i);
if(a[i] == color) temp ++;
if(temp > mx) mx = temp;
if(mx*2 > j-i+1) ++ans;
}
}
}
struct Fenwick_tree {
int n = 4e5 + 5;
int b[n+5];
void clear() {
Rep(i,1,n) b[i] = 0;
}
void updatePoint(int u,int val) {
while(u<n) {
b[u] += val;
u += (u&(-u));
}
}
int getPrefix(int u) {
if(u <= 0) return 0;
int ans=0;
while(u) {
ans += b[u];
u -= (u&(-u));
}
return ans;
}
};
Fenwick_tree bit;
void heavy(int color) {
bit.clear();
bit.updatePoint(n+1, 1);
int pre = 0;
Rep(i,1,n) {
if(a[i] == color) ++pre;
ans += bit.getPrefix(2*pre - i + n);
bit.updatePoint(2*pre - i + n + 1, 1);
}
}
signed main() {
//freopen(".inp","r",stdin); freopen(".out","w",stdout);
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin>>n;
Rep(i,1,n) cin>>a[i];
compress();
// light
Rep(i,1,cnt) {
if(s[i].sz <= cunt) type[i] = 1;
}
light();
// heavy
Rep(i,1,cnt) {
if(type[i]) continue;
heavy(i);
}
cout<<ans;
}