Compilare: user.cpp: In function ‘int pairup(int)’: user.cpp:16:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[n].size();i++) ^ user.cpp:23:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[n].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:35:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cuplaj.in","r",stdin); ^ user.cpp:36:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cuplaj.out","w",stdout); ^ user.cpp:38:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&m,&k); ^ user.cpp:41:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^