Compilare: main.cpp: In function 'int main()': main.cpp:74:29: warning: array subscript has type 'char' [-Wchar-subscripts] 74 | last[i][0] = fr[a[i]]; | ^ main.cpp:75:16: warning: array subscript has type 'char' [-Wchar-subscripts] 75 | fr[a[i]] = i; | ^ main.cpp:81:29: warning: array subscript has type 'char' [-Wchar-subscripts] 81 | last[i][1] = fr[b[i]]; | ^ main.cpp:82:16: warning: array subscript has type 'char' [-Wchar-subscripts] 82 | fr[b[i]] = i; | ^