无法在STL中打印一组向量的元素

我是新的STL地图和矢量。我正在尝试打印矢量集中存在的元素。最后一个for循环用于打印元素。代码如下:

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main(){
    int arr[]={2,0,2,1,4,3,1,0};

    vector<int> v;
    set< vector<int> > st;
    //set<int> temp;
    int init=0,fin=0;
    for(int i=0;i<8;++i){
        if(find(v.begin(),v.end(),arr[i])==v.end()){//if(temp.find(arr[i])==temp.end()){
            v.push_back(arr[i]);//temp.insert(arr[i]);

        }
        else{
            st.insert(v);
            v.clear();//temp.clear();
            v.push_back(arr[i]);//temp.insert(arr[i]);
        }

    }
    set<vector<int> >::iterator itr;
    vector<int>::iterator str;
    for(itr=st.begin();itr!=st.end();++itr){
        for(str=itr->begin();str!=itr->end();++str){
            cout<<*str<<" ";
        }
        cout<<endl;
    }
    return 0;

}

错误是:

a.cpp:26:11: error: no viable overloaded '='
                        for(str=itr->begin();str!=itr->end();++str){
                            ~~~^~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/include/c++/v1/iterator:1258:7: note: candidate function (the implicit copy assignment operator) not viable: no known conversion from '__wrap_iter<const_pointer>'
      to 'const __wrap_iter<int *>' for 1st argument
class __wrap_iter
      ^
a.cpp:34:2: error: unknown type name 'a'
        a.cpp:26:10: error: no viable overloaded '='
        ^
a.cpp:34:3: error: cannot use dot operator on a type
        a.cpp:26:10: error: no viable overloaded '='