Compilare: main.cpp: In function 'int main()': main.cpp:7:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("facebook.in", "r", stdin); ^ main.cpp:8:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("facebook.out", "w", stdout); ^ main.cpp:9:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] int n, k; scanf("%d %d", &n, &k); ^ main.cpp:11:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] int x; scanf("%d", &x); ^