Compilare: user.cpp: In function ‘int main()’: user.cpp:40:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i <= n; i++) ^ user.cpp:47:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (a <= power[62 - j - 1]) ^ user.cpp:49:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (b <= power[62 - j]) ^ user.cpp:24:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hacker3.in","r",stdin); ^ 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("hacker3.out", "w", stdout); ^ user.cpp:26:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &n); ^ user.cpp:31:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld", &v[i].a, &v[i].b); ^ user.cpp:43:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld", &v[i].a, &v[i].b); ^