65.Median of two Sorted Arrays

class Solution {
/**
 * @param A: An integer array.
 * @param B: An integer array.
 * @return: a double whose format is *.5 or *.0
 */
public double findMedianSortedArrays(int[] A, int[] B) {
    // write your code here
    int lenA = A.length;
    int lenB = B.length;
    int totalLen = lenA + lenB;
    if (totalLen % 2 == 0) {
        int sum = findKth(A, 0, B, 0, totalLen / 2) + findKth(A, 0, B, 0, 1 + totalLen / 2);
        return sum / 2.0;
    } else {
        return findKth(A, 0, B, 0, 1 + totalLen / 2);
    }
}

private int findKth(int[] A, int startA, int[] B, int startB, int k) {
    if (startA >= A.length) return B[startB + k - 1];
    if (startB >= B.length) return A[startA + k - 1];
    if (k == 1) return Math.min(A[startA], B[startB]);
    int a = ((startA + k / 2) > A.length) ? Integer.MAX_VALUE : A[startA + k / 2 - 1];
    int b = ((startB + k / 2) > B.length) ? Integer.MAX_VALUE : B[startB + k / 2 - 1];
    if (a == b) {
        return a;
    } else if (a > b) {
        return findKth(A, startA, B, startB + k / 2, k - k / 2);
    } else {
        return findKth(A, startA + k / 2, B, startB, k - k / 2);   
    }
}
}