Compilare: user.cpp: In function ‘void construct()’: user.cpp:18:61: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j <= D[i - 1].size () - P2[i - 1] - 1; ++ j) { ^ user.cpp:16:9: warning: variable ‘x’ set but not used [-Wunused-but-set-variable] int x, y, z; ^ user.cpp:16:12: warning: variable ‘y’ set but not used [-Wunused-but-set-variable] int x, y, z; ^ user.cpp:16:15: warning: variable ‘z’ set but not used [-Wunused-but-set-variable] int x, y, z; ^