{
 std::vector<int> VEC[10]{{8,88,888,809},{7,7},{923}};  //  10 size, 100 initial value
 //std::vector<int> VEC[10];  //  10 size, 100 initial value
 //std::vector<int> VEC[10]={{}};  //  10 size, 100 initial value
 VEC[0].push_back(10);
 VEC[1].push_back(11);
 VEC[2].push_back(12);
 VEC[1].push_back(19);
 VEC[1].push_back(29);
 for (int k=0;k<4;k++)
 for(int i=0;i<VEC[k].size();i++) cout<<"VEC["<<k<<"]["<<i<<"] = "<<VEC[k][i]<<endl;
 return;
}
=====================================================

Processing vector_array.C...
VEC[0][0] = 8
VEC[0][1] = 88
VEC[0][2] = 888
VEC[0][3] = 809
VEC[0][4] = 10
VEC[1][0] = 7
VEC[1][1] = 7
VEC[1][2] = 11
VEC[1][3] = 19
VEC[1][4] = 29
VEC[2][0] = 923
VEC[2][1] = 12