25 lines
997 B
JavaScript
25 lines
997 B
JavaScript
var BigInteger = require('jsbn').BigInteger;
|
|
var bi = function(n, b) { return new BigInteger(n.toString(), b ? b : 10); };
|
|
function calcPi() {
|
|
var q=bi(1), r=bi(0), t=bi(1), k=bi(1), n=bi(3), l=bi(3);
|
|
var one=bi(1), two=bi(2), three=bi(3), four=bi(4), seven=bi(7), ten=bi(10);
|
|
while (true) {
|
|
if (q.multiply(four).add(r).subtract(t).compareTo(n.multiply(t)) < 0) {
|
|
process.stdout.write(n.toString());
|
|
nr = (r.subtract(n.multiply(t))).multiply(ten);
|
|
n = (q.multiply(three).add(r)).multiply(ten).divide(t).subtract(n.multiply(ten));
|
|
q = q.multiply(ten);
|
|
r = nr;
|
|
} else {
|
|
nr = q.shiftLeft(1).add(r).multiply(l);
|
|
nn = q.multiply(k).multiply(seven).add(two).add(r.multiply(l)).divide(t.multiply(l));
|
|
q = q.multiply(k);
|
|
t = t.multiply(l);
|
|
l = l.add(two);
|
|
k = k.add(one);
|
|
n = nn;
|
|
r = nr;
|
|
}
|
|
}
|
|
}
|
|
calcPi();
|