Compilare: user.cpp: In function ‘void dfsgraph(int)’: user.cpp:19:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<v[x].size();i++) ^ user.cpp: In function ‘void dfstrans(int)’: user.cpp:28:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<p[x].size();i++) ^ user.cpp: In function ‘void kosaraju()’: user.cpp:51:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<l[i].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:62:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,x,y; ^ user.cpp:60:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in","r",stdin); ^ user.cpp:61:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out","w",stdout); ^ user.cpp:63:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:65:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^