/*
 * Calculate PI using the sequence method with the given precision.
 */

function calculatePi(precision) {
  let estimate = 0
  for(let i = 0; i < precision; i++) {
    const divisor = i * 2 + 1
    const isEven = i % 2 == 0

    if (isEven) {
      estimate = estimate + 4/divisor
    } else {
      estimate = estimate - 4/divisor
    }
  }
  return estimate
}

function calculatePiCryptic(p) {
  let e = 0
  for(let i = 0; i < p; i++) {
    e = i % 2 == 0 ? e + 4 / (i * 2 + 1) : e - 4 / (i * 2 + 1)
  }
  return e
}

const pi = calculatePi(10000)
const piCryptic = calculatePiCryptic(10000)

console.log(pi)
console.log(piCryptic)