Compilare: user.cpp: In function ‘int main()’: user.cpp:42:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<q[i].size();j++) printf("%i ",q[i][j]); ^ user.cpp:26:33: 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:27:35: 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:28:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i",&n,&m); ^ user.cpp:31:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i",&x,&y); ^