fibonacci数列js

function fibonacciRecursive(n) {
    if (n <= 1) return n;
    return fibonacciRecursive(n - 1) + fibonacciRecursive(n - 2);
}

function fibonacciIterative(n) {
    let a = 0, b = 1, c;
    if (n === 0) return a;
    for (let i = 2; i <= n; i++) {
        c = a + b;
        a = b;
        b = c;
    }
    return b;
}

function fibonacciDynamic(n) {
    let fib = [0, 1];
    for (let i = 2; i <= n; i++) {
        fib[i] = fib[i - 1] + fib[i - 2];
    }
    return fib[n];
}

function fibonacciBigInt(n) {
    let a = BigInt(0), b = BigInt(1);
    for (let i = 2; i <= n; i++) {
        let c = a + b;
        a = b;
        b = c;
    }
    return b;
}