Compilare: user.cpp: In function ‘big sc()’: user.cpp:15:9: warning: unused variable ‘cnt’ [-Wunused-variable] int cnt = 0; ^ user.cpp:16:9: warning: unused variable ‘num’ [-Wunused-variable] int num = 0; ^ user.cpp: In function ‘big operator-(big, big)’: user.cpp:54:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] a.d[i] -= ((i < b.d.size()) ? b.d[i]:0) + t; ^