Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:16:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<g[nod].size(); i++) ^ user.cpp: In function ‘bool ok(int)’: user.cpp:38:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<g[nod].size(); j++) ^ user.cpp: In function ‘int main()’: user.cpp:89:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("salvare.in", "r", stdin); ^ user.cpp:90:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("salvare.out", "w", stdout); ^ user.cpp:92:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &k); ^ user.cpp:95:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^