Submission #639198

#	Time	Username	Problem	Language	Result	Execution time	Memory
639198		Pietra	Mobile (BOI12_mobile)	C++14	80 / 100	1071 ms	16588 KiB

mobile

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

const int maxn = 2e6 + 5 ;
const int inf = 2e9 + 5 ;

double n, l, x[maxn], y[maxn] ;

bool check(double r){

    double f = 0 ;

    for(int i = 1 ; i <= n ; i++){
        double dx = sqrt((r*r) - (y[i]*y[i])) ;
        double ini = x[i] - dx, fim = x[i] + dx ;
        if(ini <= f) f = max(f, fim) ;
    }

    return (f >= l) ;
}

int32_t main(){

    cin >> n >> l ;

    for(int i = 1 ; i <= n ; i++) cin >> x[i] >> y[i] ;

    double ini = 0, fim = inf*1.00, mid ;
    int ct = 44 ;

    while(ct--){
        mid = (ini + fim)/2 ;
        if(check(mid)) fim = mid ;
        else ini = mid ;
    }

    cout << fixed << setprecision(5) << fim << "\n" ;

}

• 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: 0 / 5
• Subtask 19: 0 / 5
• Subtask 20: 0 / 5
• Subtask 21: 0 / 5