Submission #95855

#	Time	Username	Problem	Language	Result	Execution time	Memory
95855		Kastanda	Potemkin cycle (CEOI15_indcyc)	C++11	100 / 100	983 ms	1400 KiB

indcyc

#include<bits/stdc++.h>
using namespace std;
const int N = 1009;
int n, m, qu[N], P[N];
bitset < N > M, S, is[N];
vector < int > Adj[N];
inline void Prnt(int fxd, int v, int u)
{
    M = S = 0;
    memset(P, 0, sizeof(P));
    for (int &w : Adj[fxd])
        M[w] = 1;
    int l = 0, r = 0;
    qu[r ++] = v;
    S[v] = 1;
    while (r - l)
    {
        int nw = qu[l ++];
        for (int &w : Adj[nw])
            if (w != fxd && !S[w] && !(M[nw] && M[w]))
            {
                S[w] = 1;
                P[w] = nw;
                if (!M[w])
                    qu[r ++] = w;
            }
    }
    if (P[u] == 0)
        return ;
    vector < int > A;
    A.push_back(fxd);
    for (; u; u = P[u])
        A.push_back(u);
    for (int i = 0; i < (int)A.size(); i++)
        for (int j = i + 2; j < (int)A.size(); j++)
            if ((i != 0 || j != (int)A.size() - 1) && is[A[i]][A[j]])
                assert(0);
    for (int a : A)
        printf("%d ", a);
    printf("\n");
    exit(0);
}
int main()
{
    scanf("%d%d", &n, &m);
    for (int i = 1; i <= m; i++)
    {
        int v, u;
        scanf("%d%d", &v, &u);
        Adj[v].push_back(u);
        Adj[u].push_back(v);
        is[v][u] = is[u][v] = 1;
    }
    srand(time(0));
    for (int i = 1; i <= n; i++)
        random_shuffle(Adj[i].begin(), Adj[i].end());
    for (int fxd = 1; fxd <= n; fxd ++)
    {
        if (clock() >= CLOCKS_PER_SEC * 0.89)
            return !printf("no\n");
        M = S = 0;
        for (int &v : Adj[fxd])
            M[v] = 1;
        for (int &v : Adj[fxd])
        {
            int l = 0, r = 0;
            qu[r ++] = v;
            vector < int > A = {v};
            S[v] = 1;
            while (r - l)
            {
                int u = qu[l ++];
                for (int &w : Adj[u])
                    if (w != fxd && !S[w] && !(M[u] && M[w]))
                    {
                        S[w] = 1;
                        if (M[w])
                            A.push_back(w);
                        else
                            qu[r ++] = w;
                    }
            }
            for (int i = 0; i < (int)A.size(); i++)
                for (int j = i + 1; j < (int)A.size(); j++)
                    if (!is[A[i]][A[j]])
                        Prnt(fxd, A[i], A[j]);
        }
    }
    return !printf("no\n");
}

Compilation message (stderr)

indcyc.cpp: In function 'int main()':
indcyc.cpp:45:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~
indcyc.cpp:49:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &v, &u);
         ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10