Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:20:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(p=0; p<g[u].size(); ++p){ ^ user.cpp: In function ‘int main()’: user.cpp:35:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("clepsidra.in", "r", stdin); ^ user.cpp:36:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("clepsidra.out", "w", stdout); ^ user.cpp:37:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:39:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &j, &k); ^