Compilare: user.cpp: In function ‘int main()’: user.cpp:80:10: warning: unused variable ‘c’ [-Wunused-variable] char c; ^ user.cpp:84:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d", &n); ^ user.cpp: In function ‘char nextch()’: user.cpp:11:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, BUF_SIZE, 1, fi); ^