Submission #493533

#	Time	Username	Problem	Language	Result	Execution time	Memory
493533		imaginary_unit	Mobile (BOI12_mobile)	C++17	12 / 100	475 ms	8096 KiB

mobile

#include<bits/stdc++.h>
#define ll long long
#define fi first
#define se second
using namespace std;

int n, len, x[1'000'000], y[1'000'000];

bool ok(double r)
{
    double cur=0;
    for(int i=0; i<n; i++){
        double delta=sqrt(r*r-y[i]*y[i]), a=x[i]-delta, b=x[i]+delta;
        if(a<=cur){
            cur=max(cur, b);
        }
    }
    return cur >= len;
}

double MinRadius(double l, double r)
{
    for(int i=0; i<100; i++){
        double m=(l+r)/2;
        if(ok(m)){
            r=m;
        }
        else{
            l=m;
        }
    }
    return l;
}

int main()
{
    scanf("%d %d", &n, &len);
    for(int i=0; i<n; i++){
        scanf("%d %d", &x[i], &y[i]);
    }
    cout << fixed << setprecision(4) << MinRadius(0, 1e9+1);
    return 0;
}

Compilation message (stderr)

mobile.cpp: In function 'int main()':
mobile.cpp:37:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     scanf("%d %d", &n, &len);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~
mobile.cpp:39:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |         scanf("%d %d", &x[i], &y[i]);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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