309. Best Time to Buy and Sell Stock with Cooldown

1function maxProfit(prices: number[]): number {
2    if (prices.length === 0) return 0;
3    let f = 0, f0 = 0, f1 = -prices[0];
4    for (let i = 1; i < prices.length; i++) {
5        const price = prices[i];
6        const new_f0 = Math.max(f0, f1 + price);
7        const new_f1 = Math.max(f1, f - price);
8
9        f = f0;
10        f0 = new_f0;
11        f1 = new_f1;
12    }
13    return f0;
14}
15

1function maxProfit(prices: number[]): number {
2	const n = prices.length;
3	const memo: number[][] = Array.from({length: n}, () => Array(2).fill(-1));
4	function dfs(i: number, holding: number): number {
5		if(i >= n) return 0;
6		if(memo[i][holding] !== -1) return memo[i][holding];
7		let res = dfs(i + 1, holding);
8		if(holding) {
9			res = Math.max(res, prices[i] + dfs(i + 2, 0))
10		} else {
11			res = Math.max(res, -prices[i] + dfs(i + 1, 1))
12		}
13		return memo[i][holding] = res;
14	}
15	return dfs(0, 0);
16};