Compilare: main.cpp: In function 'bool getb()': main.cpp:47:44: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread (buff , BUFF , 1 , stdin); ^ main.cpp:56:40: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread (buff , BUFF , 1 , stdin); ^ main.cpp: In function 'int main()': main.cpp:63:44: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("arhipelag2.in" , "r" , stdin); ^ main.cpp:64:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d" , &n , &m); ^ main.cpp:65:36: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread (buff , BUFF , 1 , stdin); ^ main.cpp:151:25: warning: 'a2' may be used uninitialized in this function [-Wmaybe-uninitialized] g << a1 << ' ' << a2; ^ main.cpp:151:16: warning: 'a1' may be used uninitialized in this function [-Wmaybe-uninitialized] g << a1 << ' ' << a2; ^~~