how to declare a 3d vector in c++ code example

Example 1: howt o initialize 3d vector in c++

vector<vector<vector<int>>> dp(n+1,vector<vector<int>>(n+1,vector<int>(n+1,-1)));

Example 2: show a 3d vector in c++

// A recursive function able to print a vector
// of an arbitrary amount of dimensions.
template<typename T>
static void show(T vec)
{
  std::cout << vec;
}


template<typename T>
static void show(std::vector<T> vec)
{
  int size = vec.size();
  if (size <= 0) {
    std::cout << "invalid vector";
    return;
  }
  std::cout << '{';
  for (int l = 0; l < size - 1; l++) {
    show(vec[l]);
    std::cout << ',';
  }
  show(vec[size - 1]);
  std::cout << '}';
}