Compilare: user.cpp: In function ‘int main()’: user.cpp:43:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( i = 0; i < sol.size(); ++i ) ^ user.cpp:50:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( i = 0; i < sol.size(); ++i ){ ^ user.cpp:52:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( j = 0; j < sol[ i ].size(); ++j ) ^ user.cpp:31:27: warning: unused variable ‘s’ [-Wunused-variable] int n, m, i, j, x, y, s; ^ user.cpp: In function ‘void tarjan(int)’: user.cpp:71:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( i = 0; i < v[ nod ].size(); ++i ){ ^ user.cpp:65:15: warning: unused variable ‘j’ [-Wunused-variable] int n, i, j, fiu; ^ user.cpp: In function ‘int main()’: user.cpp:28:35: 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:29:37: 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:33:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:35:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^