Submission #729865

#	Time	Username	Problem	Language	Result	Execution time	Memory
729865		saken03	Balloons (CEOI11_bal)	C++17	100 / 100	223 ms	6976 KiB

bal

#include<bits/stdc++.h>

#define sz(x) (int)(x).size()
#define pb push_back
#define mp make_pair
#define f first
#define s second

typedef long long ll;

using namespace std;

void setIO(string name = "") {
	ios::sync_with_stdio(0);
	cin.tie(0);
	if (!name.empty()) {
		freopen((name + ".in").c_str(), "r", stdin);
		freopen((name + ".out").c_str(), "w", stdout);
	}
}

double calc_r(pair<double, double> a, double bx) {
	return (a.f - bx) * (a.f - bx) / (4 * a.s);
}

void solve() {        
	int n;
	cin >> n;

	vector<double> final_radius(n);
	stack<pair<double, double>> to_check;

	for (int i = 0; i < n; i++) {
		double x, r;
		cin >> x >> r;

		double max_r = r;

		while (!to_check.empty()) {
			pair<double, double> last = to_check.top();
			double to_last_r = calc_r(last, x);
			max_r = min(max_r, to_last_r);
			if (max_r >= last.s) {
				to_check.pop();
				continue;
			}
			else break;
		}
		to_check.push({x, max_r});
		final_radius[i] = max_r;
	}
	cout << fixed << setprecision(3);
	for (double &r : final_radius) cout << r << '\n';
}

int main() {
	setIO("");
	solve();
	return 0;
}   

Compilation message (stderr)

bal.cpp: In function 'void setIO(std::string)':
bal.cpp:17:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |   freopen((name + ".in").c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bal.cpp:18:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |   freopen((name + ".out").c_str(), "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10