Submission #949750

#	Time	Username	Problem	Language	Result	Execution time	Memory
949750		Kavelmydex	Mobile (BOI12_mobile)	C++17	100 / 100	419 ms	61800 KiB

mobile

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pi pair<int,int>
#define vi vector<int>
#define rep(i,x,n) for(int i=x; i<n; ++i)
#define For(i,n) rep(i,0,n)
#define endl "\n"
#define sp ' '
#define pb push_back
#define f first
#define s second
#define sz size()
#define all(x) (x).begin(),(x).end()
 
const int N = 4e5+10, OO = 1e18, mod = 1e9, mx = 2e6;
void tr(int a, int b){cout << a << sp << b << endl;}
void cmx(double &a, double b){a = max(a,b);}
void cmn(double &a, double b){a = min(a,b);}

int n,l; 
bool in(int x){return 0<=x && x<=l;}
vector <pi> inp,v;
bool ok(double m){
    double mx = 0;
    For(i,n){
        auto [x,y] = v[i];
        if(y > m) continue;
        double d = sqrt(m * m - y * y);
        if(x-d <= mx && mx < x+d){
            mx = x+d;
        }
    }
    return mx >= l;   
}
int32_t main() {
    ios::sync_with_stdio(0); cin.tie(0);
    cin >> n >> l;
    For(i,n){
        int x,y; cin >> x >> y;
        y = abs(y);
        inp.pb({x,y});
    }   
    For(i,n){
        int j = i, y = inp[i].s;
        while(j < n && inp[i].f == inp[j].f) y = min(y,inp[j].s), j++;
        v.pb({inp[i].f, y});
        i = j-1;
    }   inp.clear();
    n = v.sz;
    double l = 0, r = 1e10;
    For(i,60){
        double m = (l+r)/2;
        if(ok(m)) r = m;
        else l = m;
    }
    cout << fixed << setprecision(4) << r << endl;
    return 0;
}

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