Compilare: user.cpp: In function ‘int expand(int, int)’: user.cpp:14:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = x, j = y ; j < t.size() ; ++i, ++ j) { ^ user.cpp: In function ‘void preprocessz(int*)’: user.cpp:25:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1 ; i < t.size() ; ++ i) { ^ user.cpp: In function ‘int main()’: user.cpp:72:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(x < b.size()) { ^ user.cpp:77:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(y == t.size()) ^