Compilare: main.cpp: In function 'int main()': main.cpp:26:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pif.in", "r", stdin); ^ main.cpp:27:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pif.out", "w", stdout); ^ main.cpp:29:41: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &n, &k, &zv, &zt); ^