Compilare: main.cpp: In function 'int main()': main.cpp:22:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("grafc.in", "r", stdin); ^ main.cpp:23:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("grafc.out", "w", stdout); ^ main.cpp:26:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d %d\n", &k, &n, &m); ^