Compilare: user.cpp: In function ‘int main()’: user.cpp:16:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[y].size();j++) ^ user.cpp:28:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[y].size();j++) ^ user.cpp:38:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[y].size();j++) ^ user.cpp:7:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] {freopen ("hashuri.in","r",stdin); ^ user.cpp:8:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("hashuri.out","w",stdout); ^ user.cpp:10:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:12:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {scanf("%d%d",&k,&x); ^