Compilare: user.cpp: In function ‘int main()’: user.cpp:16:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[ch1]++; ^ user.cpp:19:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[ch2]++; ^ user.cpp:10:53: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%c %c %c %d", &ch1, &ch2, &ch3, &t); ^ user.cpp:13:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d ", &n); ^