Compilare: main.cpp: In function 'int main()': main.cpp:42:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("margele.in", "r", stdin); ^ main.cpp:43:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("margele.out", "w", stdout); ^ main.cpp:45:37: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d%d", &n, &k, &a, &b); ^