Compilare: main.cpp: In function 'int main()': main.cpp:19:11: warning: array subscript has type 'char' [-Wchar-subscripts] 19 | f[ s[0] ] = 1; | ~~~^ main.cpp:32:15: warning: array subscript has type 'char' [-Wchar-subscripts] 32 | f[ s[i] ]++; | ~~~^ main.cpp:33:18: warning: array subscript has type 'char' [-Wchar-subscripts] 33 | if (f[s[i]] == 1) | ~~~^ main.cpp:39:18: warning: array subscript has type 'char' [-Wchar-subscripts] 39 | f[s[p]]--; | ~~~^ main.cpp:40:22: warning: array subscript has type 'char' [-Wchar-subscripts] 40 | if (f[s[p]] == 0) | ~~~^