gistfile1.java

int[] a = { 1, 3, 4, 5,12, 3, 8 ,10, 10000, 12003 } ;

int result = 1;// 1 is the identify of the integer product

for ( int i = 0; i <= a.length ; i ++ ) {
    result = a[i] * result;
}

return result;



int [] a1 = split(a,5,0);
int [] a2 = split(a,5,1);



// machine 1
int result1 = 1;// 1 is the identify of the integer product

for ( int i = 0; i <= a.length ; i ++ ) {
    result1 = a1[i] * result1;
}

return result1;



// machine 2


int result1 = 1;// 1 is the identify of the integer product

for ( int i = 0; i <= a.length ; i ++ ) {
    result2 = a2[i] * result2;
}

return result2;


// waiting machine 1 and machine 2 to return me the results.

return result1 * result2;




Hello Hello
Si Hua


map() the first iteration

0, "Hello Hello" -->

{"Hello", "Hello"} -->

{ ("Hello", 1) 
  ("Hello", 1) } ---> ("Hello", {1, 1} ) ---> reducer

{ ("Si", 1) }   --->  ("Si", {1} ) ---> reducer
{ ("Hua", 1) }   --->  ("Hua", {1}) ---> reducer 



reducer()

"Hello", 2
"Si", 1
"Hua", 1




Hello 2
Si 1
Hua 1