Submission #687202

#	Time	Username	Problem	Language	Result	Execution time	Memory
687202		nikhil_kumart21	Mobile (BOI12_mobile)	C++17	80 / 100	1079 ms	32352 KiB

mobile

#include <bits/stdc++.h>

using namespace std;

typedef long double  ll;
#define endl "\n";

void setIO(string s) {
	freopen((s + ".in").c_str(), "r", stdin);
	freopen((s + ".out").c_str(), "w", stdout);
}
ll fun(ll x[],ll y[],int n,ll mid,ll L){
    // cout<<mid<<endl;
    ll num=0;
    for(int i=0;i<n;++i){
        if(mid<y[i])continue;
        ll d=sqrt(mid*mid-y[i]*y[i]);
        ll l=x[i]-d,r=x[i]+d;
        if(l<=num){
            num=max(num,r);
        }
        if(num>=L)return 0;
        // cout<<l<<" "<<r<<endl;
    }
    return num<L;
    
}
int main()
{
    // setIO("angry");
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);cout.tie(NULL);
    
    int n;
    ll L;
    cin>>n>>L;
    ll x[n],y[n];
    for(int i=0;i<n;++i){
        ll l,r;
        cin>>x[i]>>y[i];
    }
    
    // sort(v.begin(),v.end(),comp);
    ll l=0,r=2e9,mid,ans=0;
    while(l+1e-4<r){
        mid=l+(r-l)/2;
        if(fun(x,y,n,mid,L)){
            l=mid+1e-4;
            ans=mid;
        }
        else{
            r=mid-1e-4;
        }
    }
    cout<<fixed<<setprecision(3)<<ans<<endl;
    
}

Compilation message (stderr)

mobile.cpp: In function 'int main()':
mobile.cpp:41:12: warning: unused variable 'l' [-Wunused-variable]
   41 |         ll l,r;
      |            ^
mobile.cpp:41:14: warning: unused variable 'r' [-Wunused-variable]
   41 |         ll l,r;
      |              ^
mobile.cpp: In function 'void setIO(std::string)':
mobile.cpp:11:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |  freopen((s + ".in").c_str(), "r", stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mobile.cpp:12:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |  freopen((s + ".out").c_str(), "w", stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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