旋转数组

#include <iostream>
using namespace std;

class Solution
{
    public:
        int find_min_elem(int a[],int len);
        int min_order(int a[],int left,int right);
};
int Solution::find_min_elem(int a[],int len)
{
    if(a==nullptr||len<=0)
        return -1;
    
    int left=0;
    int right=len-1;
    int middle=left;
    
    while(a[left]>=a[right])
    {
        if(right-left==1)
        {
            return a[right];
            break;
        }
    
        int middle=(left+right)/2;    
        //特殊测试。 a[left]==a[right]&&a[left]==a[middle]三值相等。只能顺序查找 
        if(a[left]==a[right]&&a[left]==a[middle])
            return min_order(a,left,right);
            
        if(a[left]<a[middle])
            left=middle;
        else
            right=middle;
    }
    return a[middle];
}
int Solution::min_order(int a[],int left,int right)
{
    int res=a[left];
    for(int i=left+1;i<=right;++i)
    {
        if(res>a[i])
            res=a[i];
    }
    return res;
}
int main()
{
    Solution s;
    int a[]={1,0,1,1,1};
    int res=s.find_min_elem(a,sizeof(a)/sizeof(a[0]));
    if(res<0)
        cerr<<"error"<<endl;
    else
        cout<<res<<endl;
    return 0;
}