Compilare: user.cpp: In function ‘int main()’: user.cpp:18:11: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(x==1) if(a[k]) { out<<a[k]<<'\n'; a[k]=0; k++;} else { out<<b[k]<<'\n'; b[k]=0; k++; } ^ user.cpp:19:11: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(x==2) if( !a[k] || !b[k] ) { k++; out<<a[k]<<' '<<b[k]<<'\n'; a[k]=0; b[k]=0;} else { out<<a[k]<<' '<<b[k]<<'\n'; a[k]=0; b[k]=0; k++; } ^ user.cpp:20:11: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(x==3) if( !a[k] || !b[k] ) { k++; out<<a[k]<<' '<<b[k]<<' '<<b[k+1]<<'\n'; a[k]=0; b[k]=0; b[k+1]=0; } else { out<<a[k]<<' '<<b[k]<<' '<<b[k+1]<<'\n'; a[k]=0; b[k]=0; b[k+1]=0;k++;} ^