leetcode:4. Median of Two Sorted Arrays（Java实现）

leetcode测试地址：https://leetcode.com/problems/median-of-two-sorted-arrays/#/description

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)).

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

Subscribe to see which companies asked this question.

Java code：
package go.jacob.day617;

public class Demo2 {
public double findMedianSortedArrays(int[] A, int[] B) {
int m = A.length, n = B.length;
// 不论总数是奇数还是偶数，以l和r为下标的两数的均值都是medium
int l = (m + n + 1) / 2;
int r = (m + n + 2) / 2;

return (getkth(A, 0, B, 0, l) + getkth(A, 0, B, 0, r)) / 2.0;
}

private int getkth(int[] A, int aStart, int[] B, int bStart, int k) {
if (aStart >= A.length)
return B[bStart + k - 1];
if (bStart >= B.length)
return A[aStart + k - 1];
if(k==1)
return Math.mi
4000
n(A[aStart], B[bStart]);
int aMin=Integer.MAX_VALUE,bMin=Integer.MAX_VALUE;
if(aStart+k/2-1<A.length)
aMin=A[aStart+k/2-1];
if(bStart+k/2-1<B.length)
bMin=B[bStart+k/2-1];

if(aMin<bMin)
return getkth(A,aStart+k/2,B,bStart,k-k/2);
else
return getkth(A,aStart,B,bStart+k/2,k-k/2);
}
}