Submission #834294

#	Time	Username	Problem	Language	Result	Execution time	Memory
834294		Darren0724	Mobile (BOI12_mobile)	C++17	100 / 100	789 ms	35264 KiB

mobile

#include<bits/stdc++.h>
using namespace std;
#define int long long

int32_t main(){
    int n,len;cin>>n>>len;
    vector<int> x(n),y(n);
    for(int i=0;i<n;i++){
        cin>>x[i]>>y[i];
    }
    double l=0,r=2e9,m;
    int t=60;
    while(t--){
        m=(l+r)/2;
        double now=0;
        for(int i=0;i<n;i++){
            double d=m*m-y[i]*y[i];
            if(d<0){
                continue;
            }
            d=sqrtl(d);
            if(x[i]-d<=now&&x[i]+d>=now){
                now=x[i]+d;
            }
        }
        if(now>=len){
            r=m;
        }
        else{
            l=m;
        }
    }
    cout<<fixed<<setprecision(9)<<r<<endl;
    
    return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 4 / 4
• Subtask 3: 4 / 4
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• Subtask 5: 4 / 4
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• Subtask 21: 5 / 5