export function fibonacci_bigint(num: bigint): bigint { if (num < 0) { throw Error("must grater than zero"); } const bigInt = BigInt; const cached = feibonq.get(num); if (typeof cached !== "undefined") { return cached; } num = bigInt(num); for (let e = 0n; e <= num; e++) { if (feibonq.has(e)) { continue; } else { const r = feibonq.get(e) || bigInt(feibonq.get(e - 1n) || fibonacci_bigint(e - 1n)) + bigInt(feibonq.get(e - 2n) || fibonacci_bigint(e - 2n)); feibonq.set(e, r); } } return fibonacci_bigint(num);}const feibonq = new Map<bigint, bigint>([ [0n, 0n], [1n, 1n], [2n, 1n],]);