Compilare: main.cpp: In function 'int main()': main.cpp:15:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("rufe.in","r",stdin); ^ main.cpp:16:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("rufe.out","w",stdout); ^ main.cpp:17:51: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d %d %d %lld", &n, &m, &a, &b, &k); ^ main.cpp:8:5: warning: assuming signed overflow does not occur when assuming that (X - c) <= X is always true [-Wstrict-overflow] if (x<=b) ^~