Submission #1103795

#	Time	Username	Problem	Language	Result	Execution time	Memory
1103795		peteza	Balloons (CEOI11_bal)	C++14	20 / 100	132 ms	2052 KiB

bal

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

int n, x;
stack<pair<int, double>> stk;
double r;

double ry(double rx, long long x, long long y) {
    return ((x*x-2*x*y+y*y)/rx)/4;
}

double cmp(pair<int, double> e1, pair<int, double> e2, long long y) {
    return (e2.second)*(1ll*e1.first*e1.first-2ll*e1.first*y+y*y) <= (e1.second)*(1ll*e2.first*e2.first-2ll*e2.first*y+y*y);
}

int main() {
    cin.tie(0) -> sync_with_stdio(0);
    cin >> n;
    while(n--) {
        cin >> x >> r;
        while(stk.size() > 1) {
            auto e2 = stk.top(); stk.pop(); auto e1 = stk.top(); 
            if((1ll*e2.first*e2.first-2ll*x*e2.first+1ll*x*x) >= 4*e2.second*r && cmp(e1, e2, x)) continue;
            else {
                stk.push(e2);
                break;
            }
        }
        if(stk.empty()) stk.emplace(x, r);
        else stk.emplace(x, min(ry(stk.top().second, stk.top().first, x), r));
        while(stk.size() > 1) {
            auto e2 = stk.top(); stk.pop(); auto e1 = stk.top(); 
            if(e1.second <= e2.second) {stk.pop(); stk.push(e2); continue;}
            else { stk.push(e2); break; }
        }
        cout << fixed << setprecision(3) << stk.top().second << '\n';
    }
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 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