Submission #244563

#	Time	Username	Problem	Language	Result	Execution time	Memory
244563		dantoh000	Potemkin cycle (CEOI15_indcyc)	C++14	70 / 100	1095 ms	5112 KiB

indcyc

#include <bits/stdc++.h>
using namespace std;
int n,m;
vector<int> G[1005];
int K[1005][1005];
int p[1005];
queue<int> q;
int main(){
    scanf("%d%d",&n,&m);
    for (int i = 0; i < m; i++){
        int u,v;
        scanf("%d%d",&u,&v);
        G[u].push_back(v);
        G[v].push_back(u);
        K[u][v] = K[v][u] = 1;
    }
    for (int i = 1; i <= n; i++) K[i][i] = 1;
    for (int i = 1; i <= n; i++){
        for (auto U : G[i]){
            for (auto V : G[i]){
                if (!K[U][V]){
                    //printf("test %d %d %d\n",i,U,V);
                    p[U] = U;
                    q.push(U);
                    while (q.size()){
                        int u = q.front(); q.pop();
                        for (auto v: G[u]){
                            if ((v == V || !K[v][i]) && p[v] == 0){
                                p[v] = u;
                                //printf("%d -> %d\n",u,v);
                                q.push(v);
                            }
                        }
                    }
                    if (p[V]){
                        vector<int> ans;
                        int cur = V;
                        while (cur != U){
                            ans.push_back(cur);
                            cur = p[cur];
                        }
                        ans.push_back(U);
                        ans.push_back(i);
                        for (auto x : ans) printf("%d ",x);
                        return 0;
                    }
                    for (int i = 1; i <= n; i++) p[i] = 0;
                }
            }
        }
    }
    printf("no");
}

Compilation message (stderr)

indcyc.cpp: In function 'int main()':
indcyc.cpp:9:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~
indcyc.cpp:12:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d",&u,&v);
         ~~~~~^~~~~~~~~~~~~~

• 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: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10