Once you declare an array you just reserve some amount of memory. This memory contains garbage. if you try to print all values of the array just after delaring it you will see just garbage. See folowing line of code.
int alpha[50];
int i = 0;
for(i=0;<50;++i)
{
cout<<alpha[i]<<" ";
}
Initialization means providing valid values to elements for the first time.
Narue's code intializes first 25 elements of the array. You can try initializing rest.
I know I am. Therefore I am.