当重复出现数字时，二分法遍历排序出现问题，，求助

代码如下：
   我输入的数字是不同值时：没有发生故障；
   当输入两个相同的值时：发生故障；


#include <iostream>
#include <vector>
using namespace std;

class Line_1
{
private:
    int _size;
    vector<int>seq;
public:
    Line_1(vector<int>&tt);
    void List();
    void Print();
};
Line_1::Line_1(vector<int>&tt)
{
    for(int i = 0 ;i < tt.size(); ++i)
    {
        seq.push_back(tt[i]);
    }
    _size = tt.size();
}
void Line_1::List()
{
    int temp_seq;
    for(int i = 0 ; i < seq.size(); ++i)
    {
        int left = 0;
        int right = i;
        int mid;
        temp_seq = seq[i];
        while(left < right)
        {
            mid = (left + right)/2;
            if(temp_seq > seq[mid])
            {
                left = mid + 1;
            }
            else
            {
                right = mid - 1;
            }

        }
        for(int j = i ; j > left ; --j)
        {
            seq[j] = seq[j-1];
        }

        seq[left] = temp_seq;


    }
}
void Line_1::Print()
{
    for(int i = 0 ; i < _size ; ++i)
        cout << seq[i] << " ";
}

int main()
{
    int Size = 5;
    int a[Size] = {1,2,9,9,8};
    vector<int>tt(a , a+Size);
    Line_1 lin(tt);
    lin.List();
    lin.Print();

    return 0;
}