Submission #641957

#	Time	Username	Problem	Language	Result	Execution time	Memory
641957		gun_gan	Palembang Bridges (APIO15_bridge)	C++17	100 / 100	92 ms	5704 KiB

bridge

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

const int N = 1e5 + 5;
int k, n;
ll same_side = 0, l = 0, r = 0, p[N], s[N], ans;
vector<pair<int,int>> v;
priority_queue<int> lf;
priority_queue<int, vector<int>, greater<int>> rg;

void push(int x) 
{
	if(lf.empty() || x <= lf.top()) {
		lf.push(x);
		l += x;
	} else {
		rg.push(x);
		r += x;
	}

	if((int)lf.size() - 1 > rg.size()) {
		int t = lf.top();
		l -= t;
		r += t;
		lf.pop();
		rg.push(t);
	} else if(lf.size() < rg.size()) {
		int t = rg.top();
		r -= t;
		l += t;
		rg.pop();
		lf.push(t);
	}
}

int main() 
{
	cin.tie(0); ios_base::sync_with_stdio(0);

	cin >> k >> n;
	for(int i = 0; i < n; i++) {
		char a, b;
		int x, y;
		cin >> a >> x >> b >> y;
		if(a == b) {
			same_side += abs(x - y);
		} else {
			v.push_back({x, y});
		}
	}

	sort(v.begin(), v.end(), [&](auto x, auto y){
		return x.first + x.second < y.first + y.second;
	});

	for(int i = 0; i < v.size(); i++) {
		push(v[i].first);
		push(v[i].second);
		p[i] = r - l;
	}

	ans = p[v.size() - 1];
	if(k == 1) {
		cout << same_side + ans + v.size() << '\n';
		return 0;
	}

	while(!lf.empty()) lf.pop();
	while(!rg.empty()) rg.pop();

	l = 0, r = 0;
	for(int i = v.size() - 1; i >= 0; i--) {
		push(v[i].first);
		push(v[i].second);
		ans = min(ans, r - l + (i == 0 ? 0 : p[i - 1]));
	}	

	cout << same_side + ans + v.size() << '\n';
}

Compilation message (stderr)

bridge.cpp: In function 'void push(int)':
bridge.cpp:22:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::priority_queue<int, std::vector<int>, std::greater<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |  if((int)lf.size() - 1 > rg.size()) {
      |     ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
bridge.cpp: In function 'int main()':
bridge.cpp:57:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |  for(int i = 0; i < v.size(); i++) {
      |                 ~~^~~~~~~~~~

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