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답안 #95476

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
95476 2019-02-01T13:53:55 Z forestryks Printed Circuit Board (CEOI12_circuit) C++14
85 / 100
 47 ms 2936 KB 
///////////////////////////////////////////////////////////////////////////////////////////////
#include <bits/stdc++.h>
using namespace std;

#define mp make_pair
#define pb push_back
#define FAST_IO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
#define FILE_IO(x) freopen((string(x) + ".in").c_str(), "r", stdin); freopen((string(x) + ".out").c_str(), "w", stdout)
#define f first
#define s second
#define x1 x1qwer
#define y1 y1qwer
#define right right123
#define left left123
#define foreach(it, v) for (auto it : v)
#define rep(it, n) for (int it = 0; it < n; ++it)
#define forin(it, l, r) for (int it = l; it < r; ++it)
#define all(x) x.begin(), x.end()

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const double DINF = numeric_limits<double>::infinity();
const ll MOD = 1e9 + 7;
const double EPS = 1e-7;
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
mt19937 mmtw_(MOD);
uniform_int_distribution<ll> rd_;
ll randomll() { return rd_(mmtw_);}
ll rnd(ll x, ll y) { return rd_(mmtw_) % (y - x + 1) + x; }
////////////////////////////////////////////////////////////////////////////////////////////////

struct pt {
    int x, y;
    int id;
};

inline bool operator==(const pt &a, const pt &b) {
    return a.x == b.x && a.y == b.y;
}

inline pt operator-(const pt &a) {
    return {-a.x, -a.y};
}

inline pt operator-(const pt &a, const pt &b) {
    return {a.x - b.x, a.y - b.y};
}

inline ll dot(const pt &a, const pt &b) {
    return 1LL * a.x * b.x + 1LL * a.y * b.y;
}

inline ll cross(const pt &a, const pt &b) {
    return 1LL * a.x * b.y - 1LL * a.y * b.x;
}

inline ll dd0(const pt &a) {
    return dot(a, a);
}

const int MAXN = 1e5 + 5;
int n;
pt a[MAXN];
bool used[MAXN];
int ord[MAXN];

inline int md(int x) {
    if (x >= n) return x - n;
    if (x < 0) return x + n;
    return x;
}

int findLowest() {
    int s = 0;
    for (int i = 0; i < n; ++i) {
        ll cr = cross(a[i], a[s] - a[i]);
        if (cr > 0 || (cr == 0 && dd0(a[i]) < dd0(a[s]))) {
            s = i;
        }
    }
    return s;
}

int findHighest() {
    int t = 0;
    for (int i = 0; i < n; ++i) {
        ll cr = cross(a[i], a[t] - a[i]);
        if (cr < 0 || (cr == 0 && dd0(a[i]) < dd0(a[t]))) {
            t = i;
        }
    }
    return t;
}

struct cmp {
    bool operator()(int i, int j) {
        if (i == j) return false;
        if (cross(a[i], a[j]) <= 0) {
            return cross(a[j + 1] - a[j], a[i] - a[j]) > 0;
        } else {
            return cross(a[i + 1] - a[i], a[j] - a[i]) < 0;
        }
    }
};

signed main() {
    FAST_IO;
    cin >> n;
    rep(i, n) {
        cin >> a[i].x >> a[i].y;
        a[i].id = i + 1;
    }

    assert(n > 2);

    int lowest = findLowest();
    if (cross(a[md(lowest - 1)] - a[lowest], a[md(lowest + 1)] - a[lowest]) < 0) {
        reverse(a, a + n);
    }

    rotate(a, a + findLowest(), a + n);
    n = findHighest() + 1;

    for (int i = 0; i < n; ++i) {
        ord[i] = i;
    }

    sort(ord, ord + n, [](int i, int j){
        ll cr = cross(a[i], a[j]);
        if (cr != 0) return cr > 0;
        return dd0(a[i]) < dd0(a[j]);
    });

    vector<int> res;
    set<int, cmp> s;
    for (int ii = 0; ii < n; ++ii) {
        int i = ord[ii];

        bool add = (i + 1 < n && cross(a[i], a[i + 1] - a[i]) > 0);

        if (used[i]) {
            s.erase(s.find(i - 1));
        }

        if (!s.empty()) {
            int f = *s.begin();
            if (cross(a[f + 1] - a[f], a[i] - a[f]) > 0) res.push_back(a[i].id);
        } else {
            res.push_back(a[i].id);
        }

        if (add) {
            s.insert(i);
            used[i + 1] = true;
        }
    }

    sort(all(res));

    cout << res.size() << '\n';
    for (auto it : res) {
        cout << it << ' ';
    }
    cout << '\n';
}

Subtask #1
85.0 / 100.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 3 ms 376 KB Output is correct
4 Correct 3 ms 504 KB Output is correct
5 Correct 6 ms 636 KB Output is correct
6 Correct 6 ms 760 KB Output is correct
7 Correct 11 ms 760 KB Output is correct
8 Correct 5 ms 504 KB Output is correct
9 Correct 5 ms 632 KB Output is correct
10 Correct 6 ms 632 KB Output is correct
11 Correct 6 ms 504 KB Output is correct
12 Correct 9 ms 760 KB Output is correct
13 Correct 16 ms 1016 KB Output is correct
14 Correct 15 ms 1020 KB Output is correct
15 Correct 18 ms 1144 KB Output is correct
16 Correct 34 ms 1912 KB Output is correct
17 Correct 47 ms 2124 KB Output is correct
18 Runtime error 22 ms 2936 KB Execution killed with signal 11 (could be triggered by violating memory limits)
19 Runtime error 22 ms 2808 KB Execution killed with signal 11 (could be triggered by violating memory limits)
20 Runtime error 22 ms 2936 KB Execution killed with signal 11 (could be triggered by violating memory limits)