Compilare: user.cpp: In function ‘bool check(unsigned int)’: user.cpp:24:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(val[p] == x && (fr[p])) ^ user.cpp: In function ‘void sterge(unsigned int)’: user.cpp:38:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(val[p] == x) ^ user.cpp: In function ‘int main()’: user.cpp:46:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("muzica.in", "r", stdin); ^ user.cpp:47:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("muzica.out", "w", stdout); ^ user.cpp:52:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%u%u", &n, &m); ^ user.cpp:53:54: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld%lld%lld%lld", &a, &b, &c, &d, &e); ^ user.cpp:57:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%u", &x); ^