Compilare: user.cpp: In function ‘int main()’: user.cpp:38:45: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(sz >= 2 && str[stk[sz - 1]] > str[stk[sz]] && str[stk[sz]] < str[i]) { ^ user.cpp:38:60: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(sz >= 2 && str[stk[sz - 1]] > str[stk[sz]] && str[stk[sz]] < str[i]) { ^ user.cpp:38:76: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(sz >= 2 && str[stk[sz - 1]] > str[stk[sz]] && str[stk[sz]] < str[i]) { ^ user.cpp:39:47: warning: array subscript has type ‘char’ [-Wchar-subscripts] ans += max(get(str[stk[sz - 1]]), get(str[i])); ^ user.cpp:45:29: warning: array subscript has type ‘char’ [-Wchar-subscripts] fputc(str[stk[i]], fout); ^ user.cpp:20:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d " ,&type); ^ user.cpp:21:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%s " ,str + 1); ^