leetcode[33]Search in Rotated Sorted Array

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.

class Solution {
public:

int search(int A[], int n, int target) {
if(A==NULL||n==0)return -1;
int left=0,right=n-1;
int mid;
while(left<=right)
{
mid=(left+right)/2;
if(A[mid]==target)return mid;
if (A[left]<=A[mid])
{
if (target>=A[left]&&target<A[mid])
right=mid-1;
else left=mid+1;
}
else
{
if (target>A[mid]&&target<=A[right])
left=mid+1;
else right=mid-1;
}
}
return -1;
}
/*
int search(int A[], int n, int target) {
if(A==NULL||n==0)return -1;
int left=0, right=n-1;
int mid;
while(left<=right)
{
mid=(left+right)/2;
if(A[mid]==target)return mid;
if(A[mid]>=A[left])
{
if(A[mid]<target)left=mid+1;
else
{
if(target>=A[left])right=mid-1;
else left=mid+1;
}
}
else
{
if(target<A[mid])right=mid-1;
else
{
if (target<=A[right])left=mid+1;
else right=mid-1;
}
}
}
return -1;
}
*/
};