Compilare: user.cpp: In function ‘int main()’: user.cpp:14:17: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(a >= 'a' && a <= 'z' || a >= 'A' && a <= 'Z') ^ user.cpp:13:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%c",&a); ^ user.cpp:18:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%c",&ch); ^