Submission #872162

#	Time	Username	Problem	Language	Result	Execution time	Memory
872162		12345678	Balloons (CEOI11_bal)	C++17	30 / 100	136 ms	6688 KiB

bal

#include <bits/stdc++.h>

using namespace std;

const int nx=2e5+5;
double n, x[nx], mx[nx], dp[nx];
set<pair<double, long long>> ms;

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n;
    for (int i=1; i<=n; i++) cin>>x[i]>>mx[i];
    for (int i=1; i<=n; i++)
    {
        if (ms.empty()) dp[i]=mx[i], ms.insert({DBL_MAX, i});
        else
        {
            auto itr=ms.lower_bound({x[i], LLONG_MAX});
            dp[i]=min(double(mx[i]), ((x[i]-x[itr->second])*(x[i]-x[itr->second]))/(4*dp[itr->second]));
            while (dp[ms.begin()->second]<=dp[i]&&!ms.empty()) ms.erase(ms.begin());
            if (ms.empty()) ms.insert({DBL_MAX, i});
            else
            {
                long long l=ms.begin()->second;
                double a=dp[i]-dp[l], b=-2*(dp[i]*x[l]-dp[l]*x[i]), c=dp[i]*x[l]*x[l]-dp[l]*x[i]*x[i];
                double tmp=max((-b+sqrt(b*b-4*a*c))/(2*a), (-b-sqrt(b*b-4*a*c))/(2*a));
                ms.insert({tmp, i});
                while (!ms.empty()&&ms.begin()->second!=i) ms.erase(ms.begin());
            }
        }
        //cout<<i<<'\n';
        //for (auto [x, y]:ms) cout<<x<<' '<<y<<'\n';
    }
    for (int i=1; i<=n; i++) printf("%.3f\n", dp[i]);
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 10 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10