Submission #1116656

#	Time	Username	Problem	Language	Result	Execution time	Memory
1116656		who	Balloons (CEOI11_bal)	C++17	100 / 100	105 ms	11232 KiB

bal

#include <bits/stdc++.h>

using namespace std;

#define task "balloons"
#define etr "\n"
#define ll long long
#define ld long double
#define pii pair<int,int>
#define pli pair<long long,int>
#define pll pair<long long, long long>
#define fi first
#define se second
#define bg begin
#define pb push_back
#define pf push_front
#define pob pop_back
#define pof pop_front
#define lwb lower_bound
#define upb upper_bound
#define range(x, l, r) x+l, x+1+r
#define all(x) (x).bg(), (x).end()
#define compact(x) x.resize(unique(all(x)) - (x).bg())
#define sq(x) ((x)*(x))

auto start = chrono::high_resolution_clock::now();

void start_timer()
{
    start = chrono::high_resolution_clock::now();
}

ld elapsed()
{
    auto current = chrono::high_resolution_clock::now();
    ld duration = chrono::duration_cast<chrono::nanoseconds>(current - start).count();
    return duration / 1e9;
}
void freop()
{
	freopen(task".inp", "r", stdin);
	freopen(task".out", "w", stdout);
}

template<class U, class V> istream& operator >> (istream& in, pair<U, V>& p)
{
	in >> p.fi >> p.se;
	return in;
}

template<class U, class V> ostream& operator << (ostream& out, pair<U, V> p)
{
	out << "{" << p.fi << ' ' << p.se << "}";
	return out;
}

template<class T> ostream& operator << (ostream& out, vector<T>& v)
{
    out << "{";
	for (int i=0; i<v.size(); i++)
    {
        out << v[i];
        if (i != v.size() - 1) out << ", ";
    }

    out << "}";
	return out;
}
const int N=2e5, M=1e5, mod=1e9+7;

int n;
ll x[N+5], r[N+5];
long double ans[N+5];

ld calc(int i, int j)
{
    return sq(x[i] - x[j]) / (4 * ans[j]);
}

void process()
{
    cin >> n;
    for (int i=1; i<=n; i++) cin >> x[i] >> r[i];

    vector<int> st;
    st.reserve(n);

    for (int i=1; i<=n; i++)
    {
        ld val = r[i];
        while (!st.empty() && min(val, calc(i, st.back())) >= ans[st.back()])
        {
            val = min(val, calc(i, st.back()));
            st.pob();

        }

        if (!st.empty()) val = min(val, calc(i, st.back()));
        ans[i] = val;

        st.pb(i);

        cout << setprecision(3) << fixed << ans[i] << etr;
    }

}

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

	//freop();

	int t=1; //cin >> t;
	while (t--) process();

	return 0;
}

Compilation message (stderr)

bal.cpp: In function 'void freop()':
bal.cpp:41:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |  freopen(task".inp", "r", stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bal.cpp:42:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |  freopen(task".out", "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