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;

    }

*/

};