Submission #97205

# Submission time Handle Problem Language Result Execution time Memory
97205 2019-02-14T11:24:35 Z Kastanda Special graph (IZhO13_specialg) C++11
100 / 100
502 ms 28504 KB
#include<bits/stdc++.h>
#define pb push_back
using namespace std;
const int N = 100005;
int n, q, ts, M[N], P[N], C[N];
int Nxt[N], Dt[N], Len[N], OK[N], Lz[N];
set < pair < int , int > > Q[N], S[N];
vector < pair < int , int > > Cyc;
vector < int > TP;
void DFSC(int v)
{
    M[v] = ts;
    if (!Nxt[v] || M[Nxt[v]] && M[Nxt[v]] != ts)
        return ;
    if (M[Nxt[v]])
        Cyc.pb({Nxt[v], v});
    else
        P[Nxt[v]] = v, DFSC(Nxt[v]);
}
void DFS(int v)
{
    M[v] = 1;
    if (Nxt[v] && !C[Nxt[v]] && !M[Nxt[v]])
        DFS(Nxt[v]);
    TP.push_back(v);
}
inline void Push(int v)
{
    auto it = Q[v].lower_bound({v, -1});
    while (it != Q[v].end() && it->first == v)
    {
        OK[it->second] = 1;
        Len[it->second] += Lz[v];
        S[v].erase({it->second, it->first});
        it = Q[v].erase(it);
    }
    while (S[v].size() && S[v].rbegin()->first > Dt[v])
    {
        Q[v].erase({S[v].rbegin()->second, S[v].rbegin()->first});
        S[v].erase(*S[v].rbegin());
    }
    int nxt = Nxt[v];
    if (S[v].size() > S[nxt].size())
    {
        S[nxt].swap(S[v]);
        Q[nxt].swap(Q[v]);
        Lz[v] ++; Lz[nxt] --;
        swap(Lz[v], Lz[nxt]);
    }

    for (auto X : S[v])
    {
        S[nxt].insert(X);
        Len[X.first] += 1 + Lz[v] - Lz[nxt];
    }
    for (auto X : Q[v])
        Q[nxt].insert(X);
    S[v].clear();
    Q[v].clear();
    Lz[v] = 0;
}
void FNL(int v)
{
    M[v] ++;
    Push(v);
    if (M[Nxt[v]] < 2)
        FNL(Nxt[v]);
}
int main()
{
    scanf("%d", &n);
    memset(Dt, 63, sizeof(Dt));
    for (int i = 1; i <= n; i++)
    {
        scanf("%d", &Nxt[i]);
        if (Nxt[i] == i) Nxt[i] = 0;
        if (!Nxt[i]) Dt[i] = 0;
    }
    scanf("%d", &q);
    for (int i = 1; i <= q; i++)
    {
        int tp, v, u;
        scanf("%d%d", &tp, &v);
        if (tp == 1)
            Dt[v] = i, OK[i] = -1;
        else
        {
            scanf("%d", &u);
            S[v].insert({i, u});
            Q[v].insert({u, i});
        }
    }

    for (int i = 1; i <= n; i++)
        if (!M[i])
            ts ++, DFSC(i);
    ts = 0;
    for (auto X : Cyc)
    {
        ++ ts;
        int v = X.first, u = X.second;
        while (u != v)
            C[u] = ts, u = P[u];
        C[v] = ts;
    }
    memset(M, 0, sizeof(M));
    for (int i = 1; i <= n; i++)
        if (!M[i]) DFS(i);
    reverse(TP.begin(), TP.end());
    for (int v : TP)
        Push(v);
    memset(M, 0, sizeof(M));
    for (int i = 1; i <= n; i++)
        if (C[i] && !M[i]) FNL(i);
    for (int i = 1; i <= q; i++)
    {
        if (OK[i] == 0)
            printf("-1\n");
        if (OK[i] == 1)
            printf("%d\n", Len[i]);
    }
    return 0;
}

Compilation message

specialg.cpp: In function 'void DFSC(int)':
specialg.cpp:13:30: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
     if (!Nxt[v] || M[Nxt[v]] && M[Nxt[v]] != ts)
                    ~~~~~~~~~~^~~~~~~~~~~~~~~~~~
specialg.cpp: In function 'int main()':
specialg.cpp:71:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
specialg.cpp:75:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &Nxt[i]);
         ~~~~~^~~~~~~~~~~~~~~
specialg.cpp:79:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &q);
     ~~~~~^~~~~~~~~~
specialg.cpp:83:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &tp, &v);
         ~~~~~^~~~~~~~~~~~~~~~~
specialg.cpp:88:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d", &u);
             ~~~~~^~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 18 ms 11008 KB Output is correct
2 Correct 18 ms 10880 KB Output is correct
3 Correct 16 ms 11008 KB Output is correct
4 Correct 33 ms 11640 KB Output is correct
5 Correct 21 ms 10928 KB Output is correct
6 Correct 58 ms 12920 KB Output is correct
7 Correct 56 ms 12920 KB Output is correct
8 Correct 63 ms 12920 KB Output is correct
9 Correct 58 ms 12912 KB Output is correct
10 Correct 61 ms 13008 KB Output is correct
11 Correct 434 ms 28504 KB Output is correct
12 Correct 502 ms 24828 KB Output is correct
13 Correct 428 ms 25772 KB Output is correct
14 Correct 483 ms 24652 KB Output is correct
15 Correct 500 ms 25072 KB Output is correct
16 Correct 486 ms 24948 KB Output is correct
17 Correct 454 ms 26556 KB Output is correct
18 Correct 431 ms 26644 KB Output is correct
19 Correct 435 ms 26736 KB Output is correct
20 Correct 437 ms 28348 KB Output is correct