/in/foo.cc: In function 'int main()':
/in/foo.cc:59:22: warning: '~' on an expression of type bool [-Wbool-operation]
    cf[y]=(c^d)?(~cf[b]^cf[a]):(cf[b]^cf[a]);
                  ~~~~^
/in/foo.cc:59:22: note: did you mean to use logical not ('!')?