#include <iostream>
#include <cstdlib>

using namespace std;

int single(int array[],int Length);

int main(int argc , char *argv[])
{

    int a[]={1,1,1,2,2,3,4,4,4,5,6,7,8,8,8,8,8,8,8,9,9,9,9,9};
    int aLen = sizeof a /sizeof a[0];
    single(a, aLen);
    return 0;
}


int single(int array[],int Length)
{
     if (Length == 0) { 
        cout << "不存在" << endl;
        return 0;
    }


    int flag = Length / 4;


    if (flag == 0) { 
        cout << array[0] << endl;
        return 0;
    }
    
    cout << "Length = " << Length << " , Length / 4 = " << flag << endl;

    int f = false;
    int i =1 , s_len=0;
    int len =1;
    int min;
    for (i = 1; i < Length; i++) {
        if(array[i]==array[i-len]) {
            len++;
        } else {
            if (len > flag) {
                if (f == false) {
                    min = array[i-1];
                }
                f = true;
            }
            cout << "len = " << len << ", data = " << array[i-1] << endl;
            len = 1;
        }
    }
    
    if (Length > 0) {
       cout << "len = " << len << ", data = " << array[Length-1] << endl;
    }

    if (f) {
        cout << min << endl;
    } else {
        cout << "不存在" << endl;
    }

    return 0;
}

// 简便点的写法

#include <iostream>
#include <cstdlib>


using namespace std;




int single(int array[],int Length)
{
    int flag = Length / 4;
    cout << "Length = " << Length << " , Length / 4 = " << flag << endl;
    
    flag = flag ? flag - 1 : 0;
    
    int i;
    for(i = 0; i < Length; i++) {
<span style="white-space:pre">	</span>   if (i + flag < Length &&  array[i] == array[i + flag]) {
<span style="white-space:pre">	</span>   <span style="white-space:pre">	</span>  cout << "i = " << i << ", data = " << array[i] << endl;
<span style="white-space:pre">	</span>   <span style="white-space:pre">	</span>  break;
<span style="white-space:pre">	</span>   }
<span style="white-space:pre">	</span>}
   
    if (i >= Length) {
    <span style="white-space:pre">	</span>cout << "不存在" << endl;
<span style="white-space:pre">	</span>}
    return 0;
}


int main(int argc , char *argv[])
{


   int a[]={1,1,1,2,2,3,4,4,4,5,6,7,8,8,8,8,8,8,8,9,9,9,9,9};
    //int a[]={1,1,1,2,2,3,4,4,4,5,6,7,8,8,8,8,9,9,9,9};
    int aLen = sizeof a /sizeof a[0];
    single(a, aLen);
    return 0;
}