Compilare: user.cpp: In function ‘int main()’: user.cpp:44:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dif2.in", "r", stdin); ^ user.cpp:45:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dif2.out", "w", stdout); ^ user.cpp:48:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &c, &n); ^ user.cpp:50:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld", &p1, &p2); ^ user.cpp:52:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^ user.cpp: In function ‘long long int cauta_elem(int)’: user.cpp:22:12: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] return last; ^ user.cpp: In function ‘long long int cauta_suma(long long int)’: user.cpp:40:12: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] return last; ^ user.cpp:22:12: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] return last; ^ user.cpp:12:26: note: ‘last’ was declared here int st=0, dr=n, mij, last; ^