Find the median or k-th element of two sorted arrays

LeetCodeFive

package com.ado.java;

public class LeetCodeFive {

    private static double findMedianOfSortedArray(int[] a, int[] b) {
        int m = a.length;
        int n = b.length;

        if ((m + n) % 2 == 0) {
            // even
            return (findKthElement(a, b, (m + n)/2, 0, m -1, 0, n - 1) +
                findKthElement(a, b, (m + n)/2 -1, 0, m - 1, 0, n -1)) * 0.5;
        } else {
            // odd
            return findKthElement(a, b, (m + n)/2, 0, m - 1, 0, n - 1);
        }
    }

    private static int findKthElement(int[] a, int[] b, int k, int aStart,
            int aEnd, int bStart, int bEnd) {
        int aLen = aEnd - aStart + 1;
        int bLen = bEnd - bStart + 1;

        if (aLen == 0) {
            return b[bStart + k];
        }

        if (bLen == 0) {
            return a[aStart + k];
        }

        if (k == 0) {
            return a[aStart] < b[bStart] ? a[aStart] : b[bStart];
        }

        int aMid = aLen * k / (aLen + bLen);
        int bMid = k - aMid - 1;

        aMid = aMid + aStart;
        bMid = bMid + bStart;

        if (a[aMid] < b[bMid]) {
            k = k - (aMid - aStart + 1);
            bEnd = bMid;
            aStart = aMid + 1;
        } else {
            k = k - (bMid - bStart + 1);
            aEnd = aMid;
            bStart = bMid + 1;
        }

        return findKthElement(a, b, k, aStart, aEnd, bStart, bEnd);
    }

    public static void main(String[] args) {
        int[] a = new int[]{1, 3, 6, 8, 10};
        int[] b = new int[]{2, 4, 5, 7};

        System.out.println(findMedianOfSortedArray(a, b));
    }
}