From 40457f0f44d3981dc071fd56871f66d7e5946af1 Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Thu, 12 May 2022 16:16:48 +0800 Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=880121.=E4=B9=B0?= =?UTF-8?q?=E5=8D=96=E8=82=A1=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6?= =?UTF-8?q?=E6=9C=BA.md=EF=BC=89=EF=BC=9A=E5=A2=9E=E5=8A=A0typescript?= =?UTF-8?q?=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0121.买卖股票的最佳时机.md | 40 ++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/problems/0121.买卖股票的最佳时机.md b/problems/0121.买卖股票的最佳时机.md index f0bc3b97..a2498bb6 100644 --- a/problems/0121.买卖股票的最佳时机.md +++ b/problems/0121.买卖股票的最佳时机.md @@ -426,6 +426,46 @@ var maxProfit = function(prices) { }; ``` +TypeScript： + +> 贪心法 + +```typescript +function maxProfit(prices: number[]): number { + if (prices.length === 0) return 0; + let buy: number = prices[0]; + let profitMax: number = 0; + for (let i = 1, length = prices.length; i < length; i++) { + profitMax = Math.max(profitMax, prices[i] - buy); + buy = Math.min(prices[i], buy); + } + return profitMax; +}; +``` + +> 动态规划 + +```typescript +function maxProfit(prices: number[]): number { + /** + dp[i][0]: 第i天持有股票的最大现金 + dp[i][1]: 第i天不持有股票的最大现金 + */ + const length = prices.length; + if (length === 0) return 0; + const dp: number[][] = []; + dp[0] = [-prices[0], 0]; + for (let i = 1; i < length; i++) { + dp[i] = []; + dp[i][0] = Math.max(dp[i - 1][0], -prices[i]); + dp[i][1] = Math.max(dp[i - 1][0] + prices[i], dp[i - 1][1]); + } + return dp[length - 1][1]; +}; +``` + + + -----------------------