Submission #310518

#	Time	Username	Problem	Language	Result	Execution time	Memory
310518		vishnu_sujith	Mobile (BOI12_mobile)	C++17	100 / 100	784 ms	16236 KiB

mobile

#include <bits/stdc++.h>

using namespace std;

#ifdef DEBUG
#define LOG(...) cerr << "[" << #__VA_ARGS__ << "]: " << repr(__VA_ARGS__) << endl;
#define MSG(args) cerr << args << "\n";
#define debug(x) x
#else
#define LOG(...)
#define MSG(args)
#define debug(x)
#endif

#define vi vector<int>
#define ii pair<int, int>
#define vii vector< ii >
#define vvi vector< vi >
#define mp make_pair
#define pb push_back
#define sz(x) (int)((x).size())
#define ms(x, v) memset((x), v, sizeof(x))
#define all(x) (x).begin(), (x).end()
#define REP(x, n) for(int x = 0; x < n; x++)
#define REPV(x, v, n) for(int x = v; x < n; x++)
#define REVE(x, n) for(int x = n; x >= 0; x--)

typedef long long ll;

int N, L;
double posX[1000010], posY[1000010];

bool can(double d)
{
    double cover = 0.0;
    REP(i, N)
    {
	double dist = sqrt(d * d - posY[i] * posY[i]);
	double lft = posX[i] - dist, rgt = posX[i] + dist;
	if(lft <= cover)
	    cover = max(cover, rgt);
    }
    return cover >= L;
}

int main()
{
    scanf("%d%d", &N, &L);
    REP(i, N)
	scanf("%lf%lf", &posX[i], &posY[i]);
    double lo = 1.0, hi = 5e8;
    while(hi - lo > 1e-3)
    {
	double mid = (lo + hi) / 2.0;
	if(can(mid))
	    hi = mid;
	else
	    lo = mid;
    }
    printf("%.7lf\n", lo);
    return 0;
}

Compilation message (stderr)

mobile.cpp: In function 'int main()':
mobile.cpp:48:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   48 |     scanf("%d%d", &N, &L);
      |     ~~~~~^~~~~~~~~~~~~~~~
mobile.cpp:50:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   50 |  scanf("%lf%lf", &posX[i], &posY[i]);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 4 / 4
• Subtask 3: 4 / 4
• Subtask 4: 4 / 4
• Subtask 5: 4 / 4
• Subtask 6: 5 / 5
• Subtask 7: 5 / 5
• Subtask 8: 5 / 5
• Subtask 9: 5 / 5
• Subtask 10: 5 / 5
• Subtask 11: 5 / 5
• Subtask 12: 5 / 5
• Subtask 13: 5 / 5
• Subtask 14: 5 / 5
• Subtask 15: 5 / 5
• Subtask 16: 5 / 5
• Subtask 17: 5 / 5
• Subtask 18: 5 / 5
• Subtask 19: 5 / 5
• Subtask 20: 5 / 5
• Subtask 21: 5 / 5