title: Number Ways Node Make Loop Size K Undirected Complete Connected Graph N Nodes
signature: number_ways_node_make_loop_size_k_undirected_complete_connected_graph_n_nodes <- function(n, k) {
test_code: 
  
  
  # SOLUTION CODE
  # ============================================
  PLACEHOLDER_CODE_BODY
  
  # TESTING CODE 
  # ============================================
  validate_solution <- function(actual, expected) {
      abs(actual - expected) < 1e-06
  }
  
  driver <- function(n, k, expected){
      if (validate_solution(PLACEHOLDER_FN_NAME(n, k), expected)){
          "PASSED"
      } else{
          "FAILED"
      }
  }
  
  main <- function() {
      cat(sprintf("TEST-0...%s\n",driver(
          16L, 2L, 
          15.0
      )))
  
  }
  
  main()
source_py: def number_ways_node_make_loop_size_k_undirected_complete_connected_graph_n_nodes(n, k):
      p = 1
      if (k % 2):
          p = (- 1)
      return ((pow((n - 1), k) + (p * (n - 1))) / n)
source_cpp: int number_ways_node_make_loop_size_k_undirected_complete_connected_graph_n_nodes(int n, int k) {
    int p = 1;
    if ( k % 2 ) p = - 1;
    return ( pow ( n - 1, k ) + p * ( n - 1 ) ) / n;
  }