From c1b2141ea20e58b031c874f55c341fbfc8b69470 Mon Sep 17 00:00:00 2001 From: fwqaaq Date: Fri, 30 Jun 2023 10:22:49 +0800 Subject: [PATCH 1/5] =?UTF-8?q?Update=200123.=E4=B9=B0=E5=8D=96=E8=82=A1?= =?UTF-8?q?=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6=E6=9C=BAIII.md=20?= =?UTF-8?q?about=20rust?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../0123.买卖股票的最佳时机III.md | 27 +++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/problems/0123.买卖股票的最佳时机III.md b/problems/0123.买卖股票的最佳时机III.md index 6ac9a576..f5b95946 100644 --- a/problems/0123.买卖股票的最佳时机III.md +++ b/problems/0123.买卖股票的最佳时机III.md @@ -413,7 +413,34 @@ function maxProfit(prices: number[]): number { }; ``` +Rust： +> 版本一 + +```rust +impl Solution { + pub fn max_profit(prices: Vec) -> i32 { + /* + * 定义 5 种状态: + * 0: 没有操作, 1: 第一次买入, 2: 第一次卖出, 3: 第二次买入, 4: 第二次卖出 + */ + let mut dp = vec![vec![0; 5]; prices.len()]; + dp[0][1] = -prices[0]; + dp[0][3] = -prices[0]; + + for (i, &p) in prices.iter().enumerate().skip(1) { + // 不操作 + // dp[i][0] = dp[i - 1][0]; + dp[i][1] = dp[i - 1][1].max(-p); + dp[i][2] = dp[i - 1][2].max(dp[i - 1][1] + p); + dp[i][3] = dp[i - 1][3].max(dp[i - 1][2] - p); + dp[i][4] = dp[i - 1][4].max(dp[i - 1][3] + p); + } + + dp[prices.len() - 1][4] + } +} +```

From 85daaae4656f0411eab2e1ec6ff1bbfa608120c1 Mon Sep 17 00:00:00 2001 From: fwqaaq Date: Fri, 30 Jun 2023 10:31:32 +0800 Subject: [PATCH 2/5] =?UTF-8?q?Update=200123.=E4=B9=B0=E5=8D=96=E8=82=A1?= =?UTF-8?q?=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6=E6=9C=BAIII.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../0123.买卖股票的最佳时机III.md | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/problems/0123.买卖股票的最佳时机III.md b/problems/0123.买卖股票的最佳时机III.md index f5b95946..7286e957 100644 --- a/problems/0123.买卖股票的最佳时机III.md +++ b/problems/0123.买卖股票的最佳时机III.md @@ -442,6 +442,24 @@ impl Solution { } ``` +> 版本二（绕） + +```rust +impl Solution { + pub fn max_profit(prices: Vec) -> i32 { + let mut dp = vec![0, -prices[0], 0, -prices[0], 0]; + + for p in prices { + dp[1] = dp[1].max(-p); + dp[2] = dp[2].max(dp[1] + p); + dp[3] = dp[3].max(dp[2] - p); + dp[4] = dp[4].max(dp[3] + p); + } + dp[4] + } +} +``` +

From 2444c084b15fce271ac3639bca32bc579c594ad1 Mon Sep 17 00:00:00 2001 From: fwqaaq Date: Fri, 30 Jun 2023 11:33:23 +0800 Subject: [PATCH 3/5] =?UTF-8?q?Update=200188.=E4=B9=B0=E5=8D=96=E8=82=A1?= =?UTF-8?q?=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6=E6=9C=BAIV.md=20a?= =?UTF-8?q?bout=20rust?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../0188.买卖股票的最佳时机IV.md | 22 +++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/problems/0188.买卖股票的最佳时机IV.md b/problems/0188.买卖股票的最佳时机IV.md index 5bed5ecc..8cfb4c1b 100644 --- a/problems/0188.买卖股票的最佳时机IV.md +++ b/problems/0188.买卖股票的最佳时机IV.md @@ -439,6 +439,28 @@ function maxProfit(k: number, prices: number[]): number { }; ``` +Rust： + +```rust +impl Solution { + pub fn max_profit(k: i32, prices: Vec) -> i32 { + let mut dp = vec![vec![0; 2 * k as usize + 1]; prices.len()]; + + for v in dp[0].iter_mut().skip(1).step_by(2) { + *v = -prices[0]; + } + + for (i, &p) in prices.iter().enumerate().skip(1) { + for j in (0..2 * k as usize - 1).step_by(2) { + dp[i][j + 1] = dp[i - 1][j + 1].max(dp[i - 1][j] - p); + dp[i][j + 2] = dp[i - 1][j + 2].max(dp[i - 1][j + 1] + p); + } + } + + dp[prices.len() - 1][2 * k as usize] + } +} +```

From e452f183adde4732da370e14dc0379ebffd0bdbe Mon Sep 17 00:00:00 2001 From: fwqaaq Date: Fri, 30 Jun 2023 13:14:26 +0800 Subject: [PATCH 4/5] =?UTF-8?q?Update=200123.=E4=B9=B0=E5=8D=96=E8=82=A1?= =?UTF-8?q?=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6=E6=9C=BAIII.md=20?= =?UTF-8?q?=E4=BD=BF=E7=94=A8=E5=85=83=E7=A5=96=E4=BC=98=E5=8C=96=E5=91=BD?= =?UTF-8?q?=E5=90=8D?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0123.买卖股票的最佳时机III.md | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/problems/0123.买卖股票的最佳时机III.md b/problems/0123.买卖股票的最佳时机III.md index 7286e957..a646b7d5 100644 --- a/problems/0123.买卖股票的最佳时机III.md +++ b/problems/0123.买卖股票的最佳时机III.md @@ -447,15 +447,15 @@ impl Solution { ```rust impl Solution { pub fn max_profit(prices: Vec) -> i32 { - let mut dp = vec![0, -prices[0], 0, -prices[0], 0]; + let (mut one_buy, mut one_sale, mut two_buy, mut two_sale) = (-prices[0], 0, -prices[0], 0); for p in prices { - dp[1] = dp[1].max(-p); - dp[2] = dp[2].max(dp[1] + p); - dp[3] = dp[3].max(dp[2] - p); - dp[4] = dp[4].max(dp[3] + p); + one_buy = one_buy.max(-p); + one_sale = one_sale.max(p + one_buy); + two_buy = two_buy.max(one_sale - p); + two_sale = two_sale.max(two_buy + p); } - dp[4] + two_sale } } ``` From c4a7033e50a8713808654ac4b179ca4883b4998f Mon Sep 17 00:00:00 2001 From: fwqaaq Date: Fri, 30 Jun 2023 13:45:44 +0800 Subject: [PATCH 5/5] =?UTF-8?q?Update=200188.=E4=B9=B0=E5=8D=96=E8=82=A1?= =?UTF-8?q?=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6=E6=9C=BAIV.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../0188.买卖股票的最佳时机IV.md | 27 +++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/problems/0188.买卖股票的最佳时机IV.md b/problems/0188.买卖股票的最佳时机IV.md index 8cfb4c1b..fb1a6898 100644 --- a/problems/0188.买卖股票的最佳时机IV.md +++ b/problems/0188.买卖股票的最佳时机IV.md @@ -462,6 +462,33 @@ impl Solution { } ``` +空间优化： + +```rust +impl Solution { + pub fn max_profit(k: i32, prices: Vec) -> i32 { + let mut dp = vec![0; 2 * k as usize + 1]; + for v in dp.iter_mut().skip(1).step_by(2) { + *v = -prices[0]; + } + + for p in prices { + for i in 1..=2 * k as usize { + if i % 2 == 1 { + // 买入 + dp[i] = dp[i].max(dp[i - 1] - p); + continue; + } + // 卖出 + dp[i] = dp[i].max(dp[i - 1] + p); + } + } + + dp[2 * k as usize] + } +} +``` +