Submission #754410

#	Time	Username	Problem	Language	Result	Execution time	Memory
754410		PanosPask	Balloons (CEOI11_bal)	C++14	30 / 100	118 ms	7100 KiB

bal

#include <bits/stdc++.h>
#define pb push_back

using namespace std;

typedef long long ll;

int n;
vector<int> active_circles;
vector<long double> radius;
vector<int> maxradius;
vector<int> position;

long double find_r2(int x1, long double r1, int x2)
{
    return ((ll)(x1 - x2) * (x1 - x2)) / (4 * r1);
}

long double allowed_radius(int i, int j)
{
    return find_r2(position[i], radius[i], position[j]);
}

int main(void)
{
    scanf("%d", &n);

    position.resize(n);
    maxradius.resize(n);
    radius.resize(n);

    for (int i = 0; i < n; i++) {
        scanf("%d %d", &position[i], &maxradius[i]);
    }

    for (int i = 0; i < n; i++) {
        bool foundbreak = false;

        while (active_circles.size() >= 2 && !foundbreak) {
            int mid = active_circles.back();
            int prv = active_circles[active_circles.size() - 2];

            if (allowed_radius(prv, i) <= allowed_radius(mid, i)) {
                active_circles.pop_back();
            }
            else
                foundbreak = true;
        }

        radius[i] = maxradius[i];
        if (!active_circles.empty())
            radius[i] = min(radius[i], allowed_radius(active_circles.back(), i));

        while (!active_circles.empty() && radius[active_circles.back()] <= radius[i])
            active_circles.pop_back();
        active_circles.pb(i);

        printf("%.3Lf\n", radius[i]);
    }

    return 0;
}

Compilation message (stderr)

bal.cpp: In function 'int main()':
bal.cpp:26:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
bal.cpp:33:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |         scanf("%d %d", &position[i], &maxradius[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