Submission #940688

#	Time	Username	Problem	Language	Result	Execution time	Memory
940688		sleepntsheep	Mobile (BOI12_mobile)	C++17	100 / 100	888 ms	35412 KiB

mobile

#include<stdio.h>
#include<math.h>
#define N 1000000



int n, L;
double x[N], y[N];

int main()
{
    scanf("%d%d",&n,&L);
    for(int i=0;i<n;++i)scanf("%lf%lf",x+i,y+i);
    double l=0,r=1e9;
    for (int iter=160;iter--;)
    {
        double m=(l+r)/2,rr=0;
        for(int i=0;i<n;++i)
        {
            if(m*m>=y[i]*y[i])
            {
                double dx=sqrt(m*m-y[i]*y[i]);
                if(x[i]-dx<=rr)
                    if(x[i]+dx>rr)rr=x[i]+dx;
            }
        }

        if(rr>=L) r=m;
        else l=m;
    }
    printf("%.6lf",r);
    
}

Compilation message (stderr)

mobile.cpp: In function 'int main()':
mobile.cpp:12:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |     scanf("%d%d",&n,&L);
      |     ~~~~~^~~~~~~~~~~~~~
mobile.cpp:13:30: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |     for(int i=0;i<n;++i)scanf("%lf%lf",x+i,y+i);
      |                         ~~~~~^~~~~~~~~~~~~~~~~~

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