Submission #881893

#	Time	Username	Problem	Language	Result	Execution time	Memory
881893		TAhmed33	Diversity (CEOI21_diversity)	C++98	64 / 100	7049 ms	6716 KiB

diversity

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAXN = 3e5 + 25;
int n, a[MAXN], q, n1;
int freq[MAXN];
int main () {
	cin >> n >> q;
	for (int i = 1; i <= n; i++) cin >> a[i];
	while (q--) {
		memset(freq, 0, sizeof(freq));
		int l, r;
		cin >> l >> r;
		for (int i = l; i <= r; i++) freq[a[i]]++;
		vector <int> x;	
		for (int i = 1; i < MAXN; i++) {
			if (freq[i]) {
				x.push_back(freq[i]);
			}
		}
		n1 = x.size();
		sort(x.begin(), x.end());
		deque <int> y;
		for (int i = n1 - 1; i >= 0; i -= 2) y.push_front(x[i]);
		for (int i = n1 - 2; i >= 0; i -= 2) y.push_back(x[i]);
		ll o = r - l + 1;
		ll rr = 0, sum = 0;
		for (auto i : y) {
			sum += rr * (rr + 1) / 2 + (o - i - rr) * (o - i - rr + 1) / 2;
			rr += i;
		}
		sum = ll(o) * ll((o + 1)) / 2 * ((ll)y.size()) - sum;
		cout << sum << '\n';
	}
}

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