Compilare: main.cpp: In function 'int main()': main.cpp:70:29: warning: array subscript has type 'char' [-Wchar-subscripts] 70 | last[i][0] = fr[a[i]]; | ^ main.cpp:71:16: warning: array subscript has type 'char' [-Wchar-subscripts] 71 | fr[a[i]] = i; | ^ main.cpp:77:29: warning: array subscript has type 'char' [-Wchar-subscripts] 77 | last[i][1] = fr[b[i]]; | ^ main.cpp:78:16: warning: array subscript has type 'char' [-Wchar-subscripts] 78 | fr[b[i]] = i; | ^