模板函数实现vector元素去重

template <typename T>//先声明模板参数 T
void RemoveSameElement1(vector<T>& v)
{
    std::unordered_set<T> existed;
    for (auto iter = v.begin(); iter != v.end();)
    {
        if (existed.find(*iter) != existed.end())
        {
            iter = v.erase(iter);
        }
        else
        {
            existed.insert(*iter);
            ++iter;
        }
    }
}

template <typename T>//先声明模板参数 T
void RemoveSameElement2(vector<T>& v)
{
    std::unordered_set<T> existed;
    vector<T> vTmp;
    vTmp.reserve(v.size());
    for (auto iter = v.begin(); iter != v.end(); ++iter)
    {
        if (existed.find(*iter) == existed.end())
        {
            existed.insert(*iter);
            vTmp.push_back(*iter);
        }
    }

    vTmp.swap(v);
}

 

调用示例：

int _tmain(int argc, _TCHAR* argv[])
{
    vector<int> v;

    v.push_back(8);
    v.push_back(1);
    v.push_back(4);
    v.push_back(2);
    v.push_back(3);
    v.push_back(4);
    v.push_back(5);
    v.push_back(4);
    v.push_back(3);
    v.push_back(1);
    v.push_back(4);
    v.push_back(6);
    v.push_back(8);
    cout << "输入：" << endl;
    for (size_t i = 0 ; i < v.size(); ++i)
    {
        cout << v[i] << " ";
    }
    cout << endl << "排序："<< endl;
    sort(v.begin(), v.end());
    for (size_t i = 0 ; i < v.size(); ++i)
    {
        cout << v[i] << " ";
    }
    cout << endl;

    RemoveSameElement1(v);

    cout << "去重：" << endl;
    sort(v.begin(), v.end());
    for (size_t i = 0 ; i < v.size(); ++i)
    {
        cout << v[i] << " ";
    }

    cout << endl;
    return 0;
}