Compilare: user.cpp: In function ‘int main()’: user.cpp:5:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "divk.in", "r", stdin ); ^ user.cpp:6:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "divk.out", "w", stdout ); ^ user.cpp:8:40: 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 ); ^ user.cpp:11:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%d", &x ); ^