Compilare: main.cpp: In function 'int main()': main.cpp:44:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("freakadebunic.in","r",stdin); ^ main.cpp:45:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("freakadebunic.out","w",stdout); ^ main.cpp:47:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^ main.cpp:48:51: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for (int i=1;i<=k;i++) scanf("%d", &x), p[x] = 1; ^ main.cpp:51:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^