Cracking the Coding Interview, 4 Edition - 150 Programming Interview Questions and Solutions

Solutions to Chapter 9 | Sorting and Searching
9.3 Given a sorted array of n integers that has been rotated an unknown number of
times, give an O(log n) algorithm that finds an element in the array. You may assume
that the array was originally sorted in increasing order.
EXAMPLE:
SOLUTION
Input: find 5 in array (15 16 19 20 25 1 3 4 5 7 10 14)
Output: 8 (the index of 5 in the array)
We can do this with a modification of binary search.
1 public static int search(int a[], int l, int u, int x) {
2 while (l =a [l]) {
10 u = m-1;
11 } else {
12 l = m+1;
13 }
14 }
15 else if (x < a[m]) u = m-1;
16 else if (x