Eroare de compilare: user.cpp: In function ‘bool dfs(int)’: user.cpp:13:36: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if (mt1[v] == -1 || !vis[mt1[v]] && dfs(mt1[v])) { ^ user.cpp: In function ‘int main()’: user.cpp:40:44: error: ‘random_shuffle’ was not declared in this scope random_shuffle(al[u].begin(), al[u].end()); ^ user.cpp:24:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cuplaj.in", "r", stdin); ^ user.cpp:25:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cuplaj.out", "w", stdout); ^