Submission #811286

#	Time	Username	Problem	Language	Result	Execution time	Memory
811286		ono_de206	Diversity (CEOI21_diversity)	C++14	64 / 100	40 ms	10828 KiB

diversity

#include<bits/stdc++.h>
using namespace std;

#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define in insert
#define all(x) x.begin(),x.end()
#define pb push_back
#define eb emplace_back
#define ff first
#define ss second

#define int long long
 
typedef long long ll;
typedef vector<int> vi;
typedef set<int> si;
typedef multiset<int> msi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;

template<typename T, typename U>
ostream & operator << (ostream &out, const pair<T, U> &c) {
	out << c.first << ' ' << c.second;
    return out;
}

template<typename T>
ostream & operator << (ostream &out, vector<T> &v) {
	const int sz = v.size();
	for (int i = 0; i < sz; i++) {
		if (i) out << ' ';
		out << v[i];
	}
    return out;
}

template<typename T>
istream & operator >> (istream &in, vector<T> &v) {
	for (T &x : v) in >> x;
    return in;
}


template<typename T>
void mxx(T &a, T b){if(b > a) a = b;}
template<typename T>
void mnn(T &a, T b){if(b < a) a = b;}

const int mxn = 3e5 + 10;
int a[mxn], cnt[mxn];

void go() {
	int n, q;
	cin >> n >> q;
	for(int i = 1; i <= n; i++) {
		cin >> a[i];
		cnt[a[i]]++;
	}
	vector<pair<int, int>> v;
	for(int i = 1; i <= 300000; i++) {
		if(cnt[i] != 0) {
			v.eb(cnt[i], i);
		}
	}
	sort(all(v));
	int tp = 1, l = 1, r = n;
	for(auto it : v) {
		for(int i = 0; i < it.ff; i++) {
			if(tp) a[l++] = it.ss;
			else a[r--] = it.ss;
		}
		tp ^= 1;
	}
	// do {
	// 	int ans = n * (n + 1) / 2;
	// 	for(int i = 1; i <= n; i++) {
	// 		if(i == 1 || a[i] != a[i - 1]) {
	// 			ans += (i - 1) * (n - i + 1);
	// 		}
	// 	}	
	// 	if(ans == 148) {
	// 		for(int i = 1; i <= n; i++) {
	// 			cout << a[i] << ' ';
	// 		}
	// 		cout << '\n';
	// 	}
	// } while(next_permutation(a + 1, a + n + 1));
	int ans = n * (n + 1) / 2;
	for(int i = 1; i <= n; i++) {
		if(i == 1 || a[i] != a[i - 1]) {
			ans += (i - 1) * (n - i + 1);
		}
	}
	cout << ans << '\n';
}

signed main() {
	// #ifndef ONO
	// freopen("file.in", "r", stdin);
	// freopen("file.out", "w", stdout);
	// #endif
	fast;
	int t = 1;
	// cin >> t;
	while(t--) {
		go();
	}
	return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 16 / 16
• Subtask 5: 26 / 26
• Subtask 6: 0 / 36