If a part of this segment overlaps with the given range
int mid = getMid ( segmentStart , segmentEnd ) ; return queryEvenParityUtil ( segmentTree , segmentStart , mid , queryStart , queryEnd , 2 * index + 1 ) + queryEvenParityUtil ( segmentTree , mid + 1 , segmentEnd , queryStart , queryEnd , 2 * index + 2 ) ; }