Submission #1249183

#	Time	Username	Problem	Language	Result	Execution time	Memory
1249183		somefolk	Mobile (BOI12_mobile)	C++20	100 / 100	506 ms	16040 KiB

mobile

#include <iostream>
#include <cmath>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <unordered_map>
#include <queue>
#include <set>
#include <unordered_set>
#include <complex>
#include <list>
#include <cassert>
#include <chrono>
#include <random>
#include <stack>
#include <iomanip>
#include <fstream>
using namespace std;

#define endl "\n"
#define int long long

const int INF = 1e9+7;
const int MOD = 1e9+7;

void solve(){
    int n;
    double m;
    cin >> n >> m;

    vector<pair<double, double>> a(n);
    for(int i = 0; i < n; i++){
        cin >> a[i].first >> a[i].second;
    }

    auto check = [&](double R){
        double r = 0;
        for(auto &[x, y] : a){
            double a = x-sqrt(R*R-y*y), b = x+sqrt(R*R-y*y);
            if(a <= r){
                r = max(r, b);
            }
        }

        return (r >= m);
    };

    double l = 1, r = 1.5e9, sol = 0;
    while(r-l > 1e-3){
        double mid = (l+r)/2;
        if(check(mid)){
            sol = mid;
            r = mid;
        } else {
            l = mid;
        }
    }

    cout << fixed << setprecision(4) << sol << endl;
}

int32_t main(){
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    int t = 1;
    // cin >> t;
    while(t--) solve();
    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
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• Subtask 10: 5 / 5
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• Subtask 12: 5 / 5
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• Subtask 15: 5 / 5
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• Subtask 19: 5 / 5
• Subtask 20: 5 / 5
• Subtask 21: 5 / 5