def binarySearch(array, target): #returns the index or the target
low = array[0]
high = array[len(array)-1]
if array[0] == target:
return 0
elif array[len(array)-1] == target:
return len(array)-1
else:
while(low <= high):
mid = int((low+high)/2)
if array[mid]==target:
return mid
elif array[mid] > target:
high = mid -1
elif array[mid] < target:
low = mid +1
return -1 #returns -1 if the target does not exist