nthFib

nthFib.js

function nthFibonacciP(n) {
  let left = 0;
  let right = 1;
  if(n < 2) {
    return n;
  }
  for(let i = 2; i <= n; i++) {
    let temp_right = right;
    right = left + right;
    left = temp_right;
  }
  return right;
}