LeetCode-Search in Rotated Sorted Array II

Analysis:

For target>A[mid]:

There is only one case that we should seach [start,mid-1]: Peak is in the left, i.e., A[start]>A[mid] && target>=A[start].

For target<A[mid]:

There is only one case that we should search [mid+1,end]: Peak is in the right, i.e., A[end]<A[mid] && target<=A[end].

Solution:

public class Solution {
    public boolean search(int[] A, int target) {
        return searchRecur(A,target,0,A.length-1);
    }
    
    public boolean searchRecur(int[] A, int target, int start, int end){
        if (start>end) return false;
        
        int mid = (start+end)/2;
        if (A[mid]==target) return true;
        
        if (A[start]==A[mid] && A[end]==A[mid])
            return ( searchRecur(A,target,start,mid-1) || searchRecur(A,target,mid+1,end) );
        
        if (target>A[mid])
            if (A[start]>A[mid] && target>=A[start]) 
                return searchRecur(A,target,start,mid-1);
            else return searchRecur(A,target,mid+1,end);
        else 
            if (A[end]<A[mid] && target<=A[end])
                return searchRecur(A,target,mid+1,end);
            else return searchRecur(A,target,start,mid-1);
        
    }
        
        
}