查找两个有序数组中的第K个元素(find kth smallest element in 2 sorted arrays)

查找两个有序数组中的第K个元素

int FindKth(int a[], int b[], int k, int astart, int aend, int bstart, int bend)
{
    int aLen = aend - astart + ;
    int bLen = bend - bstart + ;

    if (aLen == )
    {
        return b[bstart + k];
    }

    if (bLen == )
    {
        return a[astart + k];
    }

    if (k == )
    {
        return a[astart] > b[bstart] ?  b[bstart] : a[astart] ;
    }

    int amid = aLen * k / (aLen + bLen); //按比例，算出分界点
    int bmid = k - amid - ;

    amid += astart;
    bmid += bstart;

    if (a[amid] > b[bmid])
    {
        k -= (bmid - bstart + );
        aend = amid;
        bstart = bmid + ;
    }
    else
    {
        k -= (amid - astart + );
        bend = bmid;
        astart = amid + ;
    }
    return FindKth(a, b, k, astart, aend, bstart, bend);
}

int main(int argc, char* argv[])
{
    int a[] = {, , , , , , };
    int b[] = {, , , };

    printf("\nfind 0th it=%d\n", FindKth(a, b, , , , , ));
    printf("\nfind 1th it=%d\n", FindKth(a, b, , , , , ));
    printf("\nfind 2th it=%d\n", FindKth(a, b, , , , , ));
    printf("\nfind 3th it=%d\n", FindKth(a, b, , , , , ));
    printf("\nfind 4th it=%d\n", FindKth(a, b, , , , , ));
    printf("\nfind 5th it=%d\n", FindKth(a, b, , , , , ));
    printf("\nfind 6th it=%d\n", FindKth(a, b, , , , , ));
    printf("\nfind 7th it=%d\n", FindKth(a, b, , , , , ));
    printf("\nfind 8th it=%d\n", FindKth(a, b, , , , , ));
    printf("\nfind 9th it=%d\n", FindKth(a, b, , , , , ));
    printf("\nfind 10th it=%d\n", FindKth(a, b, , , , , ));

    getchar();
    return ;
}