Submission #544972

#	Time	Username	Problem	Language	Result	Execution time	Memory
544972		Sohsoh84	Palembang Bridges (APIO15_bridge)	C++17	100 / 100	219 ms	12180 KiB

bridge

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;

#define all(x)			(x).begin(),(x).end()
#define X			first
#define Y			second
#define sep			' '
#define endl			'\n'
#define debug(x)		cerr << #x << ": " <<  x << endl;

const ll MAXN = 3e5 + 10;

inline pll operator+ (const pll& a, const pll& b) {
	return {a.X + b.X, a.Y + b.Y};
}

inline pll operator- (const pll& a, const pll& b) {
	return {a.X - b.X, a.Y - b.Y};
}

int n, k;
ll pref[MAXN], suff[MAXN];
vector<int> vec;
pair<int, pll> seg[MAXN];

namespace fenwick {
	pll fen[MAXN];
	
	inline void init() {
		fill(fen, fen + MAXN, make_pair(0, 0));
	}

	inline void update(int ind, pll val) {
		for (++ind; ind < MAXN; ind += ind & -ind)
			fen[ind] = fen[ind] + val;
	}

	inline pll query(int ind) {
		pll ans = {0, 0};
		for (++ind; ind > 0; ind -= ind & -ind)
			ans = ans + fen[ind];
		
		return ans;
	}
	
	inline int median() {
		int l = 1, r = MAXN - 5, tot = query(r).X;
		while (l < r) {
			int mid = (l + r) >> 1;
			if (query(mid).X >= (tot + 1) / 2) r = mid;
			else l = mid + 1;
		}

		return l;
	}

	inline ll cost() {
		int med = median();
		pll e1 = query(med), e2 = query(MAXN - 5) - e1;
		return vec[med] * e1.X - e1.Y + e2.Y - e2.X * vec[med];
	}
}

inline int comp_ind(int x) {
	return lower_bound(all(vec), x) - vec.begin();
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> k >> n;

	ll tans = 0;
	int tn = 0;
	for (int i = 1; i <= n; i++) {
		char c1, c2;
		int a, b;
		cin >> c1 >> a >> c2 >> b;
		if (c1 == c2) tans += abs(a - b);
		else {
			seg[++tn] = {a + b, {min(a, b), max(a, b)}};
			vec.push_back(a);
			vec.push_back(b);
			tans++;
		}
	}

	n = tn;
	vec.push_back(-1);
	sort(all(vec));
	vec.resize(unique(all(vec)) - vec.begin());
	sort(seg + 1, seg + n + 1);

	for (int i = 1; i <= n; i++) {
		fenwick::update(comp_ind(seg[i].Y.X), {1, seg[i].Y.X});
		fenwick::update(comp_ind(seg[i].Y.Y), {1, seg[i].Y.Y});
		pref[i] = fenwick::cost();
	}

	fenwick::init();
	for (int i = n; i > 0; i--) {	
		fenwick::update(comp_ind(seg[i].Y.X), {1, seg[i].Y.X});
		fenwick::update(comp_ind(seg[i].Y.Y), {1, seg[i].Y.Y});
		suff[i] = fenwick::cost();	
	}

	if (k == 1) return cout << pref[n] + tans << endl, 0;
	ll ans = pref[n];
	for (int i = 0; i <= n; i++)
		ans = min(ans, pref[i] + suff[i + 1]);

	cout << ans + tans << endl;
	return 0;
}

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