[Leetcode] Search in Rotated Sorted Array (Java)

Suppose a sorted array is rotated at some pivot unknown to you beforehand.

(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).

You are given a target value to search. If found in the array return its index, otherwise return -1.

You may assume no duplicate exists in the array.

循环数组查找，二分查找，几种情况分类讨论

public class SearchinRotatedSortedArray {
	public int search(int[] A, int target) {
		int res=-1;
		int low=0;
		int high=A.length-1;
		while(low<=high){
			int med = low+((high-low)>>1);
			if(A[med]==target)
				return med;
			else if(A[med]>target){
				if(A[high]>=A[med]){
					high=med-1;
				}else if(A[low]<=target){
					high=med-1;
				}else {
					low=med+1;
				}
			}else {
				if(A[low]<=A[med]){
					low=med+1;
				}else if(A[low]<=target){
					high=med-1;
				}else {
					low=med+1;
				}
			}
		}
		return res;
	}
	public static void main(String[] args) {
		int[] A = {1,3};
		int target= 3;
		System.out.println(new SearchinRotatedSortedArray().search(A, target));
	}
}