Compilare: user.cpp: In function ‘int main()’: user.cpp:84:22: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(good[c]) acc = (acc * 128 + c) % MOD; ^ user.cpp:85:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(!good[c] && acc) add(acc, i), acc = 0, num[i]++; ^ user.cpp:81:14: warning: variable ‘prev’ set but not used [-Wunused-but-set-variable] char prev = ' ', c = fgetc(fi); ^ user.cpp:78:42: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d%d%d", &n, &a, &r, &k); ^