Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:28:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (z = 0; z < v[x].size(); z++) { ^ user.cpp: In function ‘int main()’: user.cpp:39:8: warning: variable ‘fi’ set but not used [-Wunused-but-set-variable] FILE *fi, *g; ^ user.cpp:39:13: warning: variable ‘g’ set but not used [-Wunused-but-set-variable] FILE *fi, *g; ^ user.cpp:43:6: warning: unused variable ‘i’ [-Wunused-variable] int i, k, d, m; ^ user.cpp:43:9: warning: unused variable ‘k’ [-Wunused-variable] int i, k, d, m; ^ user.cpp:43:12: warning: unused variable ‘d’ [-Wunused-variable] int i, k, d, m; ^ user.cpp:44:7: warning: unused variable ‘c’ [-Wunused-variable] char c; ^ user.cpp:45:30: warning: unused variable ‘j’ [-Wunused-variable] unsigned long long sum = 0, j, x, y, s2 = 0, n; ^ user.cpp:46:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%llu %d", &n, &m); ^