Can someone help me? Have to make a method: public static int binarySearch(int[] a, int n) with the algorithm:

Question

Algorithm:
-------------

start <- 0
end <- a.length -1

while start <= end

if (end-start) is multipliable by 2?
index<-start + (end-start)/2
else
index <-start +(end-start+1)/2


if a[index]>n
end <-index-1
else if(a[index] start <- index + 1
else
return index

end while

return -1

Answer 1

int start = 0;
int end = a.length - 1;
while (start <= end) {
if (((end - start) % 2) == 0)
index = start + (end - start) / 2;
else
index = start + (end - start + 1) / 2;

// Note that the above could just be:
// index = start + (end - start + 1) / 2;
// in all cases, since if end-start is even
// the +1 will be truncated in the integer
// division operation

if (a[index] > n) end = index - 1;
else if (a[index] < n) start = index + 1;
else return index;
}

return -1;