Submission #866306

#	Time	Username	Problem	Language	Result	Execution time	Memory
866306		TAhmed33	Izbori (COCI22_izbori)	C++98	110 / 110	127 ms	12932 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize ("Ofast")
#pragma GCC target ("popcnt")
typedef long long ll;
inline ll trig (ll x) { return ((x * (x + 1)) >> 1); }
inline ll get2 (ll a, ll b, ll c) {
	if (c < 0) return 0;
	a = min(a, c); b = min(b, c);
	c = min(c, a + b);
	return (c - b) * (b + 1) + (c + 1) * (a - c + b + 1) - trig(a) + trig(c - b - 1);
}
const int MAXN = 2e5 + 25;
int arr[MAXN], n;
vector <int> occ[MAXN];
vector <int> d;
int a[2 * MAXN + 25];
ll solve1 (int x) {
	memset(a, 0, sizeof(a));
	ll ret = 0; int cur = 0; int sum = 0; a[MAXN] = 1;
	for (int i = 1; i <= n; i++) {
		if (arr[i] == x) {
			sum++; cur += a[sum - 1 + MAXN];
		} else {
			cur -= a[sum - 1 + MAXN]; sum--;
		}
		ret += cur; a[sum + MAXN]++;
	}
	return ret;
}
array <int, 500> p; 
ll solve2 (int x) {
	for (int i = 0; i < (int)occ[x].size(); i++) p[i] = occ[x][i];
	int u = occ[x].size(); ll ret = 0;
	//cout << x << ": \n";
	for (int i = 0; i < u - 1; i++) {
		for (int j = i + 1; j < u; j++) {
			if (2 * (j - i + 1) - 2 - p[j] + p[i] < 0) continue;
			ret += get2(p[i] - (i == 0 ? 0 : p[i - 1]) - 1, (j == u - 1 ? n + 1 : p[j + 1]) - p[j] - 1, 2 * (j - i + 1) - 2 - p[j] + p[i]);
			//cout << ret << '\n';
			if (j - i + 1 <= (p[j] - p[i] + 1) / 2) ret -= get2(p[i] - (i == 0 ? 0 : p[i - 1]) - 1, (j == u - 1 ? n + 1 : p[j + 1]) - p[j] - 1, (p[j] - p[i] + 1) / 2 - (j - i + 1));
			//cout << i << " | " << j << " " << ret << '\n';
		}
	}
	ret += u;
	return ret;
}
int main () {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> arr[i];
		d.push_back(arr[i]);
	}
	sort(d.begin(), d.end()); d.resize(unique(d.begin(), d.end()) - d.begin());
	for (int i = 1; i <= n; i++) arr[i] = lower_bound(d.begin(), d.end(), arr[i]) - d.begin();
	for (int i = 1; i <= n; i++) {
		occ[arr[i]].push_back(i);
	}
	bool flag = 1; for (int i = 1; i <= n; i++) flag |= (arr[i] <= 2);
	if (n >= 1e5 && !flag) return 0;
	ll sum = 0;
	int x = sqrt(n); while (x * x < n) x++; while (x * x > n) x--;
	for (int i = 0; i < n; i++) {
		if (occ[i].empty()) continue;
		if ((int)occ[i].size() > x) sum += solve1(i);
		else {
			sum += solve2(i);
		}
	}
	cout << sum << '\n';
}

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