<html>
<center>
b:<input placeholder="baris" id="baris" value="1"></input><br />
k:<input placeholder="kolom" id="kolom" value="273523615"></input>
<br />
<button onclick="herd_immunity()">Run</button>
<br />
<p id="hasil"></p> 
<p id="persentase"></p>
</center>
body {
  font-family: system-ui;
  background: #D9D9D9;
  color: #000;
  text-align: center;
}

input {
  margin: 4px;
  padding: 4px;
}

button {
  margin: 4px;
  background-color: #758C23;
}
function calculate_bk(x){
  let result;
  let chunkRes = x % 3;

  if (chunkRes == 0 || chunkRes == 1)
     result = Math.floor(x / 3) * 2;
  else
     result = 1 + Math.floor(x / 3) * 2;
  
  return result;
}

function process(b, k){
  let count = 0;
  let fb = calculate_bk(b);
  let fk = calculate_bk(k);
  let dimension = b * k;

  if (dimension == 1)
    count = 0;
  else if (b == 1)
    count = fk;
  else if (k == 1)
    count = fb;
  else
    count = dimension - ((b - fb) * (k - fk));

  return count;
}

function herd_immunity(){
  let b = document.getElementById("baris").value;
  let k = document.getElementById("kolom").value;
  let result = process(b, k);
  let persentase = result / (b*k) * 100;   	 
 document.getElementById("hasil").innerHTML = "Hasil: " +" "+ result + " orang";

 document.getElementById("persentase").innerHTML = "Persentase: "+ persentase.toPrecision(2) +"% ";
      
  return result;
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.