#include <iostream>
#include <vector>
using namespace std;
const int MAXN = 1005, MAXR = 200'005;
int adjmat[MAXN][MAXN];
int vis[MAXR], p[MAXR];
pair<int, int> elist[MAXR];
vector<int> oadjlist[MAXN], adjlist[MAXR];
bool ans_found = 0;
void dfs(int x, int par) {
if (ans_found) return;
vis[x] = 2;
p[x] = par;
for (int nxt : adjlist[x]) {
if (!vis[nxt]) dfs(nxt, x);
else if (vis[nxt] == 2 && !ans_found) {
ans_found = 1;
for (int curr = x; curr != nxt; curr = p[curr]) cout << elist[curr].first << ' ';
cout << elist[nxt].first;
}
if (ans_found) return;
}
vis[x] = 1; // not useful anymore
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int nodes, edges; cin >> nodes >> edges;
memset(adjmat, -1, sizeof(adjmat));
for (int i = 0; i < edges; i++) {
int a, b; cin >> a >> b;
elist[i] = { a, b }; elist[i + edges] = { b, a };
adjmat[a][b] = i; adjmat[b][a] = i + edges;
oadjlist[a].push_back(b); oadjlist[b].push_back(a);
}
for (int i = 1; i <= nodes; i++) {
int sz = oadjlist[i].size();
for (int j = 0; j < sz; j++)
for (int k = 0; k < j; k++) {
int a = oadjlist[i][j], b = oadjlist[i][k];
if (adjmat[a][b] == -1) {
adjlist[adjmat[a][i]].push_back(adjmat[i][b]);
adjlist[adjmat[b][i]].push_back(adjmat[i][a]);
}
}
}
for (int i = 0; i < edges * 2; i++)
if (!vis[i])
dfs(i, -1);
if (!ans_found) cout << "no";
return 0;
}
Compilation message
indcyc.cpp: In function 'int main()':
indcyc.cpp:29:2: error: 'memset' was not declared in this scope
29 | memset(adjmat, -1, sizeof(adjmat));
| ^~~~~~
indcyc.cpp:3:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
2 | #include <vector>
+++ |+#include <cstring>
3 | using namespace std;
