Median Of Two Sorted Array的尋找k 的解法

public class SolutionBySearchK {
	public double findMedianSortedArrays(int A[], int B[]) {
		int lena = A.length;
		int lenb = B.length;
		int len = lena + lenb;
		if (len % 2 == 0) {
			return (findMedianCore(A, B, 0, lena - 1, 0, lenb - 1, len / 2) + findMedianCore(
					A, B, 0, lena - 1, 0, lenb - 1, len / 2 + 1)) / 2;
		} else {
			return findMedianCore(A, B, 0, lena - 1, 0, lenb - 1, len / 2 + 1);
		}
	}

	public double findMedianCore(int[] A, int[] B, int astart, int aend,int bstart, int bend, int k) {
		int lena = aend - astart + 1;
		int lenb = bend - bstart + 1; 
		if(lena>lenb)
			return findMedianCore(B,A,bstart,bend,astart,aend,k);
		 
		if(lena<=0)
			return B[bstart+k-1];
	    if(k==1) 
			 return A[astart]>B[bstart]?B[bstart]:A[astart];
		  
		int pa=k/2>lena?lena:k/2; 
		int pb=k-pa;
		if(A[astart+pa-1]==B[bstart+pb-1]) 
			return A[astart+pa-1]; 
		else if(A[astart+pa-1]>B[bstart+pb-1])
			return findMedianCore(A,B,astart,aend,bstart+pb,bend,k-pb);
		else                           
			return findMedianCore(A,B,astart+pa,aend,bstart,bend,k-pa);
	  }
}

很好的一種解法！