Compilare: user.cpp: In function ‘int main()’: user.cpp:40:16: warning: operation on ‘l’ may be undefined [-Wsequence-point] v[t][++l] = v[t][l - 1] * d[i]; ^~~ user.cpp:42:16: warning: operation on ‘l’ may be undefined [-Wsequence-point] v[t][++l] = v[t][l - 1] * v[last][j + 1]; ^~~ user.cpp:45:16: warning: operation on ‘l’ may be undefined [-Wsequence-point] v[t][++l] = v[t][l - 1] / d[i]; ^~~ user.cpp:9:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divizori.in", "r", stdin); ^ user.cpp:10:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divizori.out", "w", stdout); ^ user.cpp:13:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^