Compilare: user.cpp: In function ‘int main()’: user.cpp:31:13: warning: unused variable ‘to’ [-Wunused-variable] int to; ^ user.cpp:59:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < v.size() - 1; ++i) ^ user.cpp:25:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("telefon2.in","r",stdin); ^ user.cpp:26:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("telefon2.out","w",stdout); ^ user.cpp:28:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:32:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &dad[i]); ^