数组中出现次数超过一半的数字

int partition(int a[],int start,int endd)
{
    int small = start -1;
    for(int i=start;i<=endd-1;i++)
    {
        if(a[i]<a[endd])
        {
            small++;
            if(a[i]!=a[small])
            {
                int tmp = a[i];
                a[i] = a[small];
                a[small] = tmp;
            }
        }
    }
    small++;
    int tmp = a[endd];
    a[endd] = a[small];
    a[small] = tmp;
    return small;
}
int MoreThanHalfNum(int a[],int n)
{
    int middle = n/2;
    int start = 0;
    int endd = n-1;
    int index = partition(a,start,endd);
    while(index != middle)
    {
        if(index<middle)
        {
            start = index + 1;
            index = partition(a,start,endd);
        }
        else if(index>middle)
        {
            endd = index -1;
            index = partition(a,start,endd);
        }

    }
    return a[index];
}

partition函数用处比较多，在快排中用到，还可以做最小的K个数等等