1～100までの乱数を何回も生成し、1～100まですべてが出現するまでの回数を数える

何度も試してその平均を求める

でやった方がわかりやすいかな?

N = 6 // サイコロ
//N = 100
MAX = N * 10
HEIGHT = MAX + 100
function setup(){
  createCanvas(400,HEIGHT)
  histogram = []
  for(i=0;i<MAX;i++) histogram[i] = 0
  strokeWeight(0)
  total = 0
  trials = 0
}
function draw(){
  visited = {}
  for(count=0,coverage=0;coverage<N;count++){
    i = Math.floor(random(N))
    if(!visited[i]) coverage++
    visited[i] = true
  }
  total += count
  trials += 1
  background('#ffc')
  fill('black')
  text(`今回: ${count}`,10,30)
  text(`平均: ${total/trials}`,70,30)
  histogram[count] += 1
  fill('blue')
  for(i=N;i<MAX;i++){
    rect(10,i-N+40,histogram[i]*2,1)
  }
}

trials = 10000
count = 0
(0...trials).each { 
  visited = {}
  total = 0
  while true
    count += 1
    i = rand(100)
    if !visited[i] then
      visited[i] = true
      total += 1
      break if total == 100
    end
  end
}
puts count / trials