Hello,
There is a question as below:
And the answer is:
It will print either _xy or _x_y
Even though the elements may be processed out of order individualy in different threads, the final output will be produced by joining the individual reduction results in the same order. Thus, the output can never have y before x.
I don't understand that why it is saying the final combiner operation will never end up as _y_x or _yx etc???
Any explanation from anybody please...