Compilare: user.cpp: In function ‘void prel()’: user.cpp:10:9: warning: unused variable ‘j’ [-Wunused-variable] int j; ^ user.cpp: In function ‘int main()’: user.cpp:65:18: warning: array subscript has type ‘char’ [-Wchar-subscripts] i=0, ap[c]=1-ap[c]; ^ user.cpp:65:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] i=0, ap[c]=1-ap[c]; ^ user.cpp: In function ‘int opxor()’: user.cpp:119:22: warning: array subscript has type ‘char’ [-Wchar-subscripts] r=ap[s[i]]; ^