Submission #795721

#	Time	Username	Problem	Language	Result	Execution time	Memory
795721		NguyenKhang	Izbori (COCI22_izbori)	C++17	15 / 110	118 ms	13736 KiB

Main

//#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;
	vi b;

	void init(int _n) {
		n=_n;
		b.resize(n+5,0);
	}

	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) {
		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
	bit.init(2*n);
	Rep(i,1,cnt) {
		if(type[i]) continue;
		heavy(i);
	}

	cout<<ans;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:144:14: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
  144 |   if(s[i].sz <= cunt) type[i] = 1;
      |      ~~~~~~~~^~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 15
• Subtask 3: 15 / 15
• Subtask 4: 0 / 70