Compilare: main.cpp: In function 'int main()': main.cpp:17:17: warning: array subscript has type 'char' [-Wchar-subscripts] 17 | fr_a[a[i]]++; | ~~~^ main.cpp:21:17: warning: array subscript has type 'char' [-Wchar-subscripts] 21 | fr_b[b[i]]++; | ~~~^ main.cpp:22:17: warning: array subscript has type 'char' [-Wchar-subscripts] 22 | fr_a[b[i]]--; | ~~~^ main.cpp:33:21: warning: array subscript has type 'char' [-Wchar-subscripts] 33 | if (fr_b[a[i]]) { | ~~~^ main.cpp:34:37: warning: array subscript has type 'char' [-Wchar-subscripts] 34 | while (ind && fr_a[a[ind]] && a[i] < a[ind - 1]) { | ~~~~~^ main.cpp:36:27: warning: array subscript has type 'char' [-Wchar-subscripts] 36 | fr_a[a[ind]]--; | ~~~~~^ main.cpp:37:27: warning: array subscript has type 'char' [-Wchar-subscripts] 37 | fr_b[a[ind]]++; | ~~~~~^ main.cpp:40:21: warning: array subscript has type 'char' [-Wchar-subscripts] 40 | fr_b[a[i]]--; | ~~~^ main.cpp:44:21: warning: array subscript has type 'char' [-Wchar-subscripts] 44 | fr_a[a[i]]--; | ~~~^