Compilare: user.cpp: In function ‘void tarjan(int)’: user.cpp:24:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[node].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:61:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < C.size(); i++){ ^ user.cpp:64:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < C[i].size(); j++) ^ user.cpp:47:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("retele.in", "r", stdin); ^ user.cpp:48:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("retele.out", "w", stdout); ^ user.cpp:49:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:51:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^