Compilare: user.cpp: In function ‘int main()’: user.cpp:42:55: warning: array subscript has type ‘char’ [-Wchar-subscripts] mi = min(mi, o[I+1][k-1]+cost[s[I]][s[k]]+o[k+1][J]); ^ user.cpp:42:61: warning: array subscript has type ‘char’ [-Wchar-subscripts] mi = min(mi, o[I+1][k-1]+cost[s[I]][s[k]]+o[k+1][J]); ^ user.cpp:64:9: warning: unused variable ‘a’ [-Wunused-variable] int a = 'z'; ^ user.cpp:65:9: warning: unused variable ‘b’ [-Wunused-variable] int b = 'a'; ^