Compilare: user.cpp: In function ‘void back(int, int)’: user.cpp:41:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] { for(int r=0; r<L[i].size(); ++r) ^ user.cpp: In function ‘int main()’: user.cpp:67:24: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 2 has type ‘int’ [-Wformat=] printf("%ld\n",smin); ^ user.cpp:50:34: 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:50:67: 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: In function ‘void cit(int&)’: user.cpp:17:52: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++pz==DIM)fread(ax, 1, DIM, stdin), pz=0; ^ user.cpp:20:54: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++pz==DIM)fread(ax,1, DIM, stdin),pz=0; ^