Compilare: user.cpp: In function ‘int main()’: user.cpp:36:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( j = 0; j < A[i].size(); j++ ) ^ user.cpp:17:15: warning: unused variable ‘k’ [-Wunused-variable] int i, j, k, x, y, c, p, u; ^ user.cpp:17:27: warning: unused variable ‘p’ [-Wunused-variable] int i, j, k, x, y, c, p, u; ^ user.cpp:17:30: warning: unused variable ‘u’ [-Wunused-variable] int i, j, k, x, y, c, p, u; ^