p20

by akiratetsuo

JavaScript

var result = 0;

function f(a) {
  for (let i = 0; i < a.length - 1; i++) {
    if (a[i] >= 10) {
      a[i + 1] = a[i + 1] + parseInt(a[i] / 10);
      a[i] = a[i] % 10;
    }
  }
  return a;
}

var a = Array(200);
a.fill(0);
a[0] = 1;
for (let i = 1; i <= 100; i++) {
  a = f(a.map(x => x * i))
}
result = a.reduce((a, b) => a + b, 0);
document.write(result)