Submission #1122200

#	Time	Username	Problem	Language	Result	Execution time	Memory
1122200		steveonalex	Mobile (BOI12_mobile)	C++17	100 / 100	363 ms	35404 KiB

mobile

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()

ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}

ll gcd(ll a, ll b){return __gcd(a, b);}
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ll mask){return __builtin_ctzll(mask);}
int logOf(ll mask){return __lg(mask);}

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}

template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }

template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }

template <class T>
    void printArr(T& container, string separator = " ", string finish = "\n"){
        for(auto item: container) cout << item << separator;
        cout << finish;
    }


template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

void solve(){
    int n, L; cin >> n >> L;
    vector<pair<ll, ll>> a(n);
    for(int i = 0; i<n; ++i) cin >> a[i].first >> a[i].second;
    for(int i = 0; i<n; ++i) a[i].second = abs(a[i].second);
    sort(ALL(a));

    double l = 0, r = 2e9;
    for(int i = 0; i < 45; ++i) {
        double mid = (l + r) / 2;
        double ma = 0;
        for(pair<ll, ll> j: a){
            if (abs(j.second) > mid) continue;
            double r = sqrt(mid * mid - j.second * j.second);
            pair<double, double> cur = {j.first - r, j.first + r};
            maximize(cur.first, 0); minimize(cur.second, L);
            if (cur.first > cur.second) continue;

            if (cur.first <= ma) maximize(ma, cur.second);
        }

        if (ma == L) r = mid;
        else l = mid;
    }

    cout << fixed << setprecision(6) << l << "\n";
}

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    clock_t start = clock();

    solve();

    cerr << "Time elapsed: " << clock() - start << "ms!\n";
    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