Compilare: user.cpp: In function ‘int main()’: user.cpp:38:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[m].size();j++) ^ user.cpp:15:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ubuntzei.in","r",stdin); ^ user.cpp:16:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ubuntzei.out","w",stdout); ^ user.cpp:17:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:18:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&k); ^ user.cpp:20:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[i]); ^ user.cpp:24:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&i,&j,&k); ^