oj.uz

답안 #142487

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
142487 2019-08-09T09:20:32 Z popovicirobert Link (CEOI06_link) C++14
100 / 100
 687 ms 51076 KB 
#include <bits/stdc++.h>
#pragma GCC optimize ("Ofast")
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
// 217
// 44


/*const int MOD = 998244353;

inline int lgput(int a, int b) {
    int ans = 1;
    while(b > 0) {
        if(b & 1) ans = (1LL * ans * a) % MOD;
        b >>= 1;
        a = (1LL * a * a) % MOD;
    }
    return ans;
}

inline void mod(int &x) {
    if(x >= MOD)
        x -= MOD;
}

inline void add(int &x, int y) {
    x += y;
    mod(x);
}

inline void sub(int &x, int y) {
    x += MOD - y;
    mod(x);
}

inline void mul(int &x, int y) {
    x = (1LL * x * y) % MOD;
}

inline int inv(int x) {
    return lgput(x, MOD - 2);
}*/

/*int fact[], invfact[];

inline void prec(int n) {
    fact[0] = 1;
    for(int i = 1; i <= n; i++) {
        fact[i] = (1LL * fact[i - 1] * i) % MOD;
    }
    invfact[n] = lgput(fact[n], MOD - 2);
    for(int i = n - 1; i >= 0; i--) {
        invfact[i] = (1LL * invfact[i + 1] * (i + 1)) % MOD;
    }
}

inline int comb(int n, int k) {
    if(n < k) return 0;
    return (1LL * fact[n] * (1LL * invfact[k] * invfact[n - k] % MOD)) % MOD;
}*/

using namespace std;

const int INF = 1e9;

int main() {
    //ifstream cin("A.in");
    //ofstream cout("A.out");
    int i, j, n, k;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    cin >> n >> k;
    vector < vector <int> > g(n + 1);
    vector <int> to(n + 1), deg(n + 1);
    for(i = 1; i <= n; i++) {
        int a, b;
        cin >> a >> b;
        to[a] = b, deg[b]++;
        g[b].push_back(a);
    }
    vector <int> dst(n + 1, INF), vis(n + 1);
    queue <int> Q;
    int ans = 0;
    for(i = 1; i <= n; i++) {
        if(deg[i] == 0) {
            Q.push(i);
            dst[i] = 1;
            ans += (i != 1);
        }
    }
    dst[1] = 0;
    while(Q.size()) {
        int nod = Q.front();
        vis[nod] = 1;
        Q.pop();
        for(auto it : g[nod]) {
            dst[nod] = min(dst[nod], dst[it] + 1);
        }
        if(dst[nod] == k + 1) {
            dst[nod] = 1;
            ans++;
        }
        deg[to[nod]]--;
        if(deg[to[nod]] == 0) {
            Q.push(to[nod]);
        }
    }
    //cerr << ans;
    for(i = 1; i <= n; i++) {
        for(auto it : g[i]) {
            dst[i] = min(dst[i], dst[it] + 1);
        }
    }
    for(i = 1; i <= n; i++) {
        if(vis[i]) continue;
        vector <int> cyc;
        for(j = i; vis[j] == 0; j = to[j]) {
            vis[j] = 1;
            cyc.push_back(j);
        }
        priority_queue < pair <int, int> > pq;
        int sz = cyc.size();
        for(j = 0; j < sz; j++) {
            cyc.push_back(cyc[j]);
            pq.push({-dst[cyc[j]], cyc[j]});
        }
        while(pq.size()) {
            auto cur = pq.top();
            pq.pop();
            if(dst[to[cur.second]] > -cur.first + 1) {
                dst[to[cur.second]] = -cur.first + 1;
                pq.push({cur.first - 1, to[cur.second]});
            }
        }
        vector <int> nxt(2 * sz);
        int last = -1;
        for(j = 2 * sz - 1; j >= 0; j--) {
            if(dst[cyc[j]] > k) {
                last = j;
            }
            nxt[j] = last;
        }
        vector < vector <int> > anc(20, vector <int>(2 * sz));
        for(j = 0; j < 2 * sz; j++) {
            anc[0][j] = (j + k < 2 * sz ? nxt[j + k] : -1);
        }
        for(int bit = 1; bit < 20; bit++) {
            for(j = 0; j < 2 * sz; j++) {
                anc[bit][j] = (anc[bit - 1][j] == -1 ? -1 : anc[bit - 1][anc[bit - 1][j]]);
            }
        }
        int mn = INF;
        for(j = 0; j < sz; j++) {
            if(dst[cyc[j]] <= k) continue;
            int cur = 0, p = j;
            for(int bit = 19; bit >= 0; bit--) {
                if(anc[bit][p] != -1 && anc[bit][p] < j + sz) {
                    p = anc[bit][p];
                    cur += (1 << bit);
                }
            }
            mn = min(mn, cur + 1);
        }
        if(mn == INF) mn = 0;
        ans += mn;
    }

    cout << ans;

    return 0;
}

Subtask #1
100.0 / 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 504 KB Output is correct
4 Correct 5 ms 636 KB Output is correct
5 Correct 5 ms 632 KB Output is correct
6 Correct 24 ms 3480 KB Output is correct
7 Correct 34 ms 4600 KB Output is correct
8 Correct 53 ms 7296 KB Output is correct
9 Correct 82 ms 13164 KB Output is correct
10 Correct 72 ms 11912 KB Output is correct
11 Correct 202 ms 35564 KB Output is correct
12 Correct 193 ms 15240 KB Output is correct
13 Correct 296 ms 27500 KB Output is correct
14 Correct 299 ms 30900 KB Output is correct
15 Correct 466 ms 40300 KB Output is correct
16 Correct 429 ms 47436 KB Output is correct
17 Correct 573 ms 48108 KB Output is correct
18 Correct 537 ms 45028 KB Output is correct
19 Correct 687 ms 46848 KB Output is correct
20 Correct 621 ms 47008 KB Output is correct
21 Correct 603 ms 50908 KB Output is correct
22 Correct 608 ms 51076 KB Output is correct
23 Correct 535 ms 50756 KB Output is correct
24 Correct 616 ms 51068 KB Output is correct
25 Correct 651 ms 51068 KB Output is correct