Submission #103864

#	Time	Username	Problem	Language	Result	Execution time	Memory
103864		E869120	Palembang Bridges (APIO15_bridge)	C++14	31 / 100	2050 ms	16084 KiB

bridge

#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;

long long K, N, M, L[100009], R[100009], cnt;

long long solve_1() {
	vector<long long>X; map<long long, long long>Map;
	for (int i = 0; i < M; i++) {
		X.push_back(L[i]);
		X.push_back(R[i]);
		Map[L[i]] += 2; Map[R[i]] += 2;
	}
	sort(X.begin(), X.end());
	X.erase(unique(X.begin(), X.end()), X.end());

	long long cx = 0, sum = 0, minx = (1LL << 60), dep = -M * 2;
	for (int i = 0; i < M; i++) sum += L[i] + R[i];
	minx = min(minx, sum);

	for (int i = 0; i < X.size(); i++) {
		sum += (X[i] - cx) * dep;
		minx = min(minx, sum);
		dep += Map[X[i]];
		cx = X[i];
	}
	return minx;
}

long long solve_val(long long val) {
	vector<long long>X; map<long long, long long>Map;
	for (int i = 0; i < M; i++) {
		if (val < L[i] || R[i] < val) {
			long long E = min(abs(L[i] - val), abs(val - R[i]));
			X.push_back(L[i] - E); Map[L[i] - E] -= 2;
			X.push_back(R[i] + E); Map[R[i] + E] -= 2;
			X.push_back(L[i]); Map[L[i]] += 2;
			X.push_back(R[i]); Map[R[i]] += 2;
		}
	}
	sort(X.begin(), X.end());
	X.erase(unique(X.begin(), X.end()), X.end());

	long long cx = -2000000000LL, sum = 0, minx = (1LL << 60), dep = 0;
	for (int i = 0; i < M; i++) sum += abs(L[i] - val) + abs(R[i] - val);
	minx = min(minx, sum);

	for (int i = 0; i < X.size(); i++) {
		sum += (X[i] - cx) * dep;
		minx = min(minx, sum);
		dep += Map[X[i]];
		cx = X[i];
	}
	return minx;
}

long long solve_2() {
	long long ans = solve_1();
	for (int i = 0; i < M; i++) {
		ans = min(ans, solve_val(L[i]));
		ans = min(ans, solve_val(R[i]));
	}
	return ans;
}

int main() {
	cin >> K >> N;
	for (int i = 0; i < N; i++) {
		char c1, c2; int cl, cr;
		cin >> c1 >> cl >> c2 >> cr;
		if (c1 != c2) {
			if (cl > cr) swap(cl, cr);
			L[M] = cl;
			R[M] = cr;
			cnt++; M++;
		}
		else cnt += 1LL * abs(cl - cr);
	}

	if (K == 1) {
		cout << solve_1() + cnt << endl;
	}
	if (K == 2) {
		cout << solve_2() + cnt << endl;
	}
	return 0;
}

Compilation message (stderr)

bridge.cpp: In function 'long long int solve_1()':
bridge.cpp:23:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < X.size(); i++) {
                  ~~^~~~~~~~~~
bridge.cpp: In function 'long long int solve_val(long long int)':
bridge.cpp:50:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < X.size(); i++) {
                  ~~^~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 14 / 14
• Subtask 3: 9 / 9
• Subtask 4: 0 / 32
• Subtask 5: 0 / 37