Compilare: user.cpp: In function ‘int main()’: user.cpp:164:14: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] cuv[lg+1]=nu; ^ user.cpp:158:30: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,20000,stdin); ^ user.cpp: In function ‘void read(int&)’: user.cpp:36:103: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] while(buff[pos] < '0' || buff[pos] > '9') if(++pos == 20000) fread(buff, 1, 20000, stdin), pos = 0; ^ user.cpp:38:137: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] while('0' <= buff[pos] && buff[pos] <= '9') {nr = nr * 10 + buff[pos] - '0';if(++pos == 20000) fread(buff, 1, 20000, stdin), pos = 0;} ^ user.cpp: In function ‘void readCh(char&)’: user.cpp:42:102: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] while(buff[pos]==' ' || buff[pos]=='\n') if(++pos == 20000) fread(buff, 1, 20000, stdin), pos = 0; ^ user.cpp:44:61: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++pos == 20000) fread(buff, 1, 20000, stdin), pos = 0; ^