Submission #1102811

#	Time	Username	Problem	Language	Result	Execution time	Memory
1102811		Zero_OP	Mobile (BOI12_mobile)	C++14	0 / 100	449 ms	44788 KiB

mobile

#include <bits/stdc++.h>

using namespace std;

#define rep(i, l, r) for(int i = (l), _r = (r); i < _r; ++i)
#define FOR(i, l, r) for(int i = (l), _r = (r); i <= _r; ++i)
#define ROF(i, r, l) for(int i = (r), _l = (l); i >= _l; --i)
#define all(v) begin(v), end(v)
#define compact(v) v.erase(unique(all(v)), end(v))
#define sz(v) (int)v.size()
#define dbg(x) "[" #x " = " << (x) << "]"

template<typename T>
bool minimize(T& a, const T& b){
    if(a > b) return a = b, true; return false;
}

template<typename T>
bool maximize(T& a, const T& b){
    if(a < b) return a = b, true; return false;
}

using ll = long long;
using ld = long double;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template<typename T> T random_int(T l, T r){ return uniform_int_distribution<T>(l, r)(rng); }
template<typename T> T random_real(T l, T r){ return uniform_real_distribution<T>(l, r)(rng); }

const ld eps = 1e-6;

struct point{
    ld x, y;
    point(ld x = 0, ld y = 0) : x(x), y(y) {}

    ld norm() const { return x * x + y * y; }
    ld dist() const { return sqrtl(norm()); }

    friend istream& operator >> (istream& in, point& p) { return in >> p.x >> p.y; }
};

void testcase(){
    int n;
    ld L;
    cin >> n >> L;
    vector<point> points(n);
    for(int i = 0; i < n; ++i) cin >> points[i];

    ld l = 0, r = sqrt(2e18) + 10;
    int rep = 0;
    while(r - l > eps){
        ld mid = (l + r) / 2.0l;
        ld mid2 = mid * mid;

        ld last_cover = 0.0;
        bool ok = true;
        for(int i = 0; i < n; ++i){
            ld p = points[i].y * points[i].y;
            if(mid2 - p < eps) break;
            ld q = sqrtl(mid2 - p);
            ld cover_left = points[i].x - q;
            ld cover_right = points[i].x + q;
            if(last_cover - cover_left > eps){
                last_cover = max(last_cover, cover_right);
            } else{
                ok = false;
                break;
            }
        }

        ok |= (last_cover - L > eps);

        if(ok) r = mid;
        else l = mid;
    }

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

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    #define filename "task"
    if(fopen(filename".inp", "r")){
        freopen(filename".inp", "r", stdin);
        freopen(filename".out", "w", stdout);
    }

    int T = 1; //cin >> T;
    while(T--) testcase();

    return 0;
}

Compilation message (stderr)

mobile.cpp: In function 'bool minimize(T&, const T&)':
mobile.cpp:15:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   15 |     if(a > b) return a = b, true; return false;
      |     ^~
mobile.cpp:15:35: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   15 |     if(a > b) return a = b, true; return false;
      |                                   ^~~~~~
mobile.cpp: In function 'bool maximize(T&, const T&)':
mobile.cpp:20:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   20 |     if(a < b) return a = b, true; return false;
      |     ^~
mobile.cpp:20:35: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   20 |     if(a < b) return a = b, true; return false;
      |                                   ^~~~~~
mobile.cpp: In function 'void testcase()':
mobile.cpp:50:9: warning: unused variable 'rep' [-Wunused-variable]
   50 |     int rep = 0;
      |         ^~~
mobile.cpp: In function 'int main()':
mobile.cpp:86:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   86 |         freopen(filename".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
mobile.cpp:87:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |         freopen(filename".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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