Submission #312544

#	Time	Username	Problem	Language	Result	Execution time	Memory
312544		fatemetmhr	Balloons (CEOI11_bal)	C++17	10 / 100	454 ms	9720 KiB

bal

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

const int MAXN = 1000 * 1000 + 10;
const long long INF = 1LL * 1000 * 1000 * 1000 * 1000 * 1000 * 1000 + 10;

int n, r[MAXN], x[MAXN];
long double ans[MAXN];
stack <int> balloon;

bool check(int ind1, int ind2, double mid)
{
    long double d = (x[ind1] - x[ind2]) * (x[ind1] - x[ind2]) + (ans[ind2] - mid) * (ans[ind2] - mid);
    if(sqrt(d) < mid + ans[ind2]) return 0;
    else return 1;
}
int main ()
{
    cout<<fixed<<setprecision(15);
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);

    cin >> n >> x[0] >> r[0];
    balloon.push(0);
    ans[0] = r[0];
    cout << r[0] << endl;
    for(int i = 1; i < n; i++){
        cin >> x[i] >> r[i];
        ans[i] = r[i];
        while(!balloon.empty() and r[balloon.top()] <= ans[i]){
            long double lo = 0, hi = ans[i] + 0.001;
            while(hi - lo > 0.001){
                long double mid = (hi + lo) / 2.0;
                if(check(i, balloon.top(), mid)) lo = mid;
                else hi = mid;
            }
            ans[i] = min(ans[i], lo);
            if(ans[i] >= r[balloon.top()]) balloon.pop();
        }
        if(!balloon.empty()){
            long double lo = 0, hi = ans[i] + 0.001;
            while(hi - lo > 0.001){
                long double mid = (hi + lo) / 2.0;
                if(check(i, balloon.top(), mid)) lo = mid;
                else hi = mid;
            }
            ans[i] = min(ans[i], lo);
        }
        balloon.push(i);
        cout << ans[i] << '\n';
    }
    return 0;
}

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