Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:26:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < list[node].size(); i++) { ^ user.cpp:53:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < list[node].size(); i++) ^ user.cpp:56:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < list[node].size(); i++) ^ user.cpp:62:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < list[node].size(); i++) { ^ user.cpp:65:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i != list[node].size() - 1) aux = (aux * r[i + 1]) % mod; ^ user.cpp: In function ‘int main()’: user.cpp:76:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("karb2.in","r",stdin); ^ user.cpp:77:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("karb2.out","w",stdout); ^ user.cpp:79:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ user.cpp:81:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp:86:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^