Submission #46591

#	Time	Username	Problem	Language	Result	Execution time	Memory
46591		aome	Palembang Bridges (APIO15_bridge)	C++17	100 / 100	341 ms	40240 KiB

bridge

#include <bits/stdc++.h>

using namespace std;

const int N = 100005;

int m, n;
long long res;
long long f[2][N];
pair<int, int> a[N];
vector< pair<int, int> > vec;

struct SegmentTree {
	pair<int, long long> T[4 * 2 * N];

	void init() {
		for (int i = 0; i < 4 * 2 * N; ++i) T[i] = {0, 0};
	}

	#define mid ((l + r) >> 1)

	void upd(int i, int l, int r, int p) {
		if (l == r) {
			T[i] = {1, vec[l].first}; return; 
		}
		if (mid >= p) upd(i << 1, l, mid, p);
		else upd(i << 1 | 1, mid + 1, r, p);
		T[i] = {T[i << 1].first + T[i << 1 | 1].first, T[i << 1].second + T[i << 1 | 1].second};
	}

	int find(int i, int l, int r, int k) {
		if (l == r) return l;
		if (k <= T[i << 1].first) return find(i << 1, l, mid, k);
		return find(i << 1 | 1, mid + 1, r, k - T[i << 1].first);
	}

	long long get(int i, int l, int r, int L, int R) {
		if (L > r || l > R) return 0;
		if (L <= l && r <= R) return T[i].second;
		return get(i << 1, l, mid, L, R) + get(i << 1 | 1, mid + 1, r, L, R);
	}

	#undef mid
} IT;

int main() {
	ios::sync_with_stdio(false);
	cin >> m >> n;
	int cnt = 0;
	for (int i = 1; i <= n; ++i) {
		char x, y;
		++cnt;
		cin >> x >> a[cnt].first >> y >> a[cnt].second;
		if (a[cnt].first > a[cnt].second) {
			swap(a[cnt].first, a[cnt].second);
		}
		if (x == y) res += a[cnt].second - a[cnt].first, cnt--;
	}
	n = cnt;
	sort(a + 1, a + 1 + n, [&] (pair<int, int> x, pair<int, int> y) {
		return x.first + x.second < y.first + y.second;
	});
	for (int i = 1; i <= n; ++i) {
		vec.push_back({a[i].first, i * 2}), vec.push_back({a[i].second, i * 2 + 1});
	}
	sort(vec.begin(), vec.end());
	for (int i = 1; i <= n; ++i) {
		a[i].first = lower_bound(vec.begin(), vec.end(), make_pair(a[i].first, i * 2)) - vec.begin();
		a[i].second = lower_bound(vec.begin(), vec.end(), make_pair(a[i].second, i * 2 + 1)) - vec.begin();
	}
	IT.init();
	for (int i = 1; i <= n; ++i) {
		IT.upd(1, 0, n * 2 - 1, a[i].first);	
		IT.upd(1, 0, n * 2 - 1, a[i].second);
		int p = IT.find(1, 0, n * 2 - 1, i);
		f[0][i] = IT.get(1, 0, n * 2 - 1, p + 1, n * 2 - 1) - IT.get(1, 0, n * 2 - 1, 0, p);
	}
	IT.init();
	for (int i = n; i >= 1; --i) {
		IT.upd(1, 0, n * 2 - 1, a[i].first);	
		IT.upd(1, 0, n * 2 - 1, a[i].second);
		int p = IT.find(1, 0, n * 2 - 1, n - i + 1);
		f[1][i] = IT.get(1, 0, n * 2 - 1, p + 1, n * 2 - 1) - IT.get(1, 0, n * 2 - 1, 0, p);		
	}
	if (m == 1) cout << f[0][n] + res + n;
	else {
		long long mn = 1e18;
		for (int i = 0; i <= n; ++i) mn = min(mn, f[0][i] + f[1][i + 1]);
		cout << mn + res + n;
	}
}

• Subtask 1: 8 / 8
• Subtask 2: 14 / 14
• Subtask 3: 9 / 9
• Subtask 4: 32 / 32
• Subtask 5: 37 / 37