Compilare: main.cpp: In function 'char get_ch()': main.cpp:31:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ main.cpp: In function 'int main()': main.cpp:68:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (t=0;t<L[nr].size();t++){ ~^~~~~~~~~~~~~ main.cpp:34:31: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread (buff,1,DIMBUFF,fin); ^