leetcode[4]Median of Two Sorted Arrays

There are two sorted arrays A and B 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)).

double findKth(int A[],int m,int B[],int n,int k)

{

    if(m>n)

    return findKth(B,n,A,m,k);

    if(m==0)

    return B[k-1];

    if(k==1)

    return min(A[0],B[0]);

    int pa=min(k/2,m);

    int pb=k-pa;

    if(A[pa-1]<B[pb-1])

    {

       return findKth(A+pa,m-pa,B,n,k-pa); 

    }

    else if(A[pa-1]>B[pb-1])

    {

       return findKth(A,m,B+pb,n-pb,k-pb);  

    }

    else if(A[pa-1]==B[pb-1])

    {

        return A[pa-1];

    }

}

class Solution {

public:

    double findMedianSortedArrays(int A[], int m, int B[], int n) 

    {

        int total=m+n;

        return (total%2)?(findKth(A,m,B,n,total/2+1)):((findKth(A,m,B,n,total/2)+findKth(A,m,B,n,total/2+1))/2);

    }

};