0518-coin-change-ii.ts

function change(amount: number, coins: number[]): number {
    let table = Array(amount + 1).fill(0);
    table[0] = 1;
    for (let coin of coins) {
        for (let i = 0; i < table.length; i++) {
            if (coin <= i) {
                table[i] += table[i - coin];
            }
        }
    }
    return table[amount];
}