Median of Two Sorted Arrays

There are two sorted arrays nums1 and nums2 of size m and n respectively.

Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)).

You may assume nums1 and nums2 cannot be both empty.

Example 1:

nums1 = [1, 3]
nums2 = [2]

The median is 2.0

Example 2:

nums1 = [1, 2]
nums2 = [3, 4]

The median is (2 + 3)/2 = 2.5

class Solution {
    public double findMedianSortedArrays(int[] A, int[] B) {
        int m = A.length;
        int n = B.length;
        if (m > n) { // to ensure m<=n
            int[] temp = A; A = B; B = temp;
            int tmp = m; m = n; n = tmp;
        }
        // The Binary search is of partitions
        int iMin = 0, iMax = m, halfLen = (m + n + 1) / 2;
        while (iMin <= iMax) {
            int i = (iMin + iMax) / 2;
            int j = halfLen - i;
            if (i < iMax && B[j-1] > A[i]){
                iMin = i + 1; // i is too small
            }
            else if (i > iMin && A[i-1] > B[j]) {
                iMax = i - 1; // i is too big
            }
            else { // i is perfect
                int maxLeft = 0;
                if (i == 0) 
                    maxLeft = B[j-1];
                else if (j == 0)
                    maxLeft = A[i-1];
                else
                    maxLeft = Math.max(A[i-1], B[j-1]);
                if ( (m + n) % 2 == 1 )
                    return maxLeft;

                int minRight = 0;
                if (i == m)
                    minRight = B[j];
                else if (j == n)
                    minRight = A[i];
                else
                    minRight = Math.min(B[j], A[i]);

                return (maxLeft + minRight) / 2.0;
            }
        }
        return 0.0;
    }
}