How to get the correct thread id and value

I am trying to send vector as data to pthread. But when I am trying to print the thread id , its coming garbage value.

If I run this code with single thread, it works fine. But when I run it with 2 threads, its not working.

#include <iostream>
#include <pthread.h>
#include <vector>
using namespace std;

struct val {
    int data;
    int sData;

};

void *foo(void *a)
{
   vector <val *>* b = (vector <val *>*)a;

   for (val *it : *b) {
   std::cout <<" thread " <<it->data;
   std::cout <<" &&&  " <<it->sData<<"-----------"<<endl;
   }
}

int main()
{
  pthread_t thr[2];

  for (int j = 0; j < 2; j++) {
      std::vector <val*> a;
      for (int i = 0; i< 10; i++) {
        val* t = new val();
        t->data = j;
        t->sData = j*10;
        a.push_back(t);
      }
      pthread_create(&thr[j], NULL, &foo, &a);//creating threads
}
  pthread_join(thr[0],NULL);
  pthread_join(thr[1],NULL);
  return 0;
}


expected output:
thread 0 &&& 0
....
....
thread 1 &&& 10
thread 1 &&& 10
....
....