Submission #35272

#	Time	Username	Problem	Language	Result	Execution time	Memory
35272		cheater2k	Palembang Bridges (APIO15_bridge)	C++14	31 / 100	203 ms	4536 KiB

bridge

#include <bits/stdc++.h>
using namespace std;

const int N = 100005;

int k, n;
int sz;
long long ans;
pair<int,int> a[N];
vector<int> z;

long long solve1() {
	if (n == 0) return 0;
	long long res = 0;
	int med = z[z.size() / 2];
	for (int i = 0; i < z.size(); ++i) {
		res += abs(med - z[i]);
	}
	return res;
}

long long calc(int x, int y) {
	if (x == z.size()) x = 1e9; else x = z[x];
	if (y == z.size()) y = 1e9; else y = z[y];
	long long res = 0;
	for (int i = 1; i <= n; ++i) {
		int dx = abs(x - a[i].first) + abs(x - a[i].second);
		int dy = abs(y - a[i].first) + abs(y - a[i].second);
		res += min(dx, dy);
	}
	return res;
}

long long solve2() {
	if (n == 0) return 0;
	long long res = 1e18;
	for (int i = 0; i < z.size(); ++i) {
		int l = 0, r = z.size() - 1;
		while(l < r) {
			int mid = ((l + r) >> 1);
			if (calc(i, mid) > calc(i, mid + 1)) l = mid + 1;
			else r = mid;
		}
		res = min(res, calc(i, l));
	}
	return res;
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0);
	cin >> k >> n;
	for (int i = 1; i <= n; ++i) {
		char p, q;
		int s, t;
		cin >> p >> s >> q >> t;
		if (p == q) ans += abs(s - t);
		else ++sz, a[sz] = make_pair(min(s, t), max(s, t));
	}
	n = sz;
	for (int i = 1; i <= n; ++i) {
		z.push_back(a[i].first);
		z.push_back(a[i].second);
	}
	sort(z.begin(), z.end());

	ans += n;
	if (k == 1) ans += solve1(); else ans += min(solve1(), solve2());

	printf("%lld\n", ans);
}

Compilation message (stderr)

bridge.cpp: In function 'long long int solve1()':
bridge.cpp:16:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < z.size(); ++i) {
                    ^
bridge.cpp: In function 'long long int calc(int, int)':
bridge.cpp:23:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if (x == z.size()) x = 1e9; else x = z[x];
        ^
bridge.cpp:24:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if (y == z.size()) y = 1e9; else y = z[y];
        ^
bridge.cpp: In function 'long long int solve2()':
bridge.cpp:37:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < z.size(); ++i) {
                    ^

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