Compilare: user.cpp: In function ‘void back(int, int)’: user.cpp:42:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] { for(int ll,cc,r=0; r<L[i].size(); ++r) ^ user.cpp: In function ‘int main()’: user.cpp:80:24: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 2 has type ‘int’ [-Wformat=] printf("%ld\n",smin); ^ user.cpp:56:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("suma3.in","r",stdin); freopen("suma3.out","w",stdout); ^ user.cpp:56:67: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("suma3.in","r",stdin); freopen("suma3.out","w",stdout); ^ user.cpp:57:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&a,&b); ^ user.cpp:59:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] { scanf("%d",&v[i][j]); ^