Compilare: user.cpp: In function ‘int main()’: user.cpp:15:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("magicnum.in","r",stdin); ^ user.cpp:16:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("magicnum.out","w",stdout); ^ user.cpp:18:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^ user.cpp: In function ‘int bs(int)’: user.cpp:13:8: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] return last;} ^ user.cpp: In function ‘int main()’: user.cpp:41:8: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] cnt=cnt+r-l+1;} ^ user.cpp:39:12: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] l=bs(x-1)+1; ^