算法题之有序数组被折断后的查找

int searchDisorderedArray(int a[], int key, int begin, int end)
{
    if(begin == end && a[begin] != key)
        return -1;

    int mid = (begin+end)/2;

    if(a[mid] == key)
        return mid;

    if(a[mid] > a[end])
    {
        if(key >= a[begin] && key <=a[mid])
            return searchDisorderedArray(a, key, begin, mid-1);
        else
            return searchDisorderedArray(a, key, mid+1, end);
    }
    else
    {
        if(key >= a[mid] && key <=a[end])
            return searchDisorderedArray(a, key, mid+1, end);
        else
            return searchDisorderedArray(a, key, begin, mid-1);
    }
}