From 44afcb2b898f571be7c6b5ab10b33470612e98e2 Mon Sep 17 00:00:00 2001 From: wzs <1014355013@qq.com> Date: Wed, 12 May 2021 23:21:50 +0800 Subject: [PATCH 1/6] =?UTF-8?q?=E6=B7=BB=E5=8A=A00121.=E4=B9=B0=E5=8D=96?= =?UTF-8?q?=E8=82=A1=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6=E6=9C=BA?= =?UTF-8?q?=E5=92=8CJava=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 | 30 +++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) 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 3d564892..941d4397 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 @@ -196,9 +196,37 @@ public: ## 其他语言版本 - Java： +``` java +class Solution { // 动态规划解法 + public int maxProfit(int[] prices) { + // 可交易次数 + int k = 1; + // [天数][交易次数][是否持有股票] + int[][][] dp = new int[prices.length][k + 1][2]; + + // bad case + dp[0][0][0] = 0; + dp[0][0][1] = Integer.MIN_VALUE; + dp[0][1][0] = Integer.MIN_VALUE; + dp[0][1][1] = -prices[0]; + + for (int i = 1; i < prices.length; i++) { + for (int j = k; j >= 1; j--) { + // dp公式 + dp[i][j][0] = Math.max(dp[i - 1][j][0], dp[i - 1][j][1] + prices[i]); + dp[i][j][1] = Math.max(dp[i - 1][j][1], dp[i - 1][j - 1][0] - prices[i]); + } + } + + return dp[prices.length - 1][k][0] > 0 ? dp[prices.length - 1][k][0] : 0; + } +} +``` + + + Python： From afaca167dc4166584e6d7ba3db7ad1c25524cf1f Mon Sep 17 00:00:00 2001 From: wzs <1014355013@qq.com> Date: Wed, 12 May 2021 23:22:42 +0800 Subject: [PATCH 2/6] =?UTF-8?q?=E6=B7=BB=E5=8A=A00122.=E4=B9=B0=E5=8D=96?= =?UTF-8?q?=E8=82=A1=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6=E6=9C=BA?= =?UTF-8?q?II=E5=92=8CJava=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../0122.买卖股票的最佳时机II.md | 22 ++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/problems/0122.买卖股票的最佳时机II.md b/problems/0122.买卖股票的最佳时机II.md index 1a9b4f7f..2e973217 100644 --- a/problems/0122.买卖股票的最佳时机II.md +++ b/problems/0122.买卖股票的最佳时机II.md @@ -133,9 +133,29 @@ public: ## 其他语言版本 - Java： +```java +class Solution { // 动态规划 + public int maxProfit(int[] prices) { + // [天数][是否持有股票] + int[][] dp = new int[prices.length][2]; + + // bad case + dp[0][0] = 0; + dp[0][1] = -prices[0]; + + for (int i = 1; i < prices.length; i++) { + // dp公式 + dp[i][0] = Math.max(dp[i - 1][0], dp[i - 1][1] + prices[i]); + dp[i][1] = Math.max(dp[i - 1][1], dp[i - 1][0] - prices[i]); + } + + return dp[prices.length - 1][0]; + } +} +``` + Python： From 7123ab82447fad9c1e387f3478905fe6aea7e852 Mon Sep 17 00:00:00 2001 From: wzs <1014355013@qq.com> Date: Wed, 12 May 2021 23:23:13 +0800 Subject: [PATCH 3/6] =?UTF-8?q?=E6=B7=BB=E5=8A=A00123.=E4=B9=B0=E5=8D=96?= =?UTF-8?q?=E8=82=A1=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6=E6=9C=BA?= =?UTF-8?q?III=E5=92=8CJava=E7=89=88=E6=9C=AC?= 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 | 35 ++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) 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 0e718cf1..f6d2efb0 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 @@ -190,9 +190,42 @@ dp[1] = max(dp[1], dp[0] - prices[i]); 如果dp[1]取dp[1]，即保持买入股 ## 其他语言版本 - Java： +```java +class Solution { // 动态规划 + public int maxProfit(int[] prices) { + // 可交易次数 + int k = 2; + + // [天数][交易次数][是否持有股票] + int[][][] dp = new int[prices.length][k + 1][2]; + + // badcase + dp[0][0][0] = 0; + dp[0][0][1] = Integer.MIN_VALUE; + dp[0][1][0] = 0; + dp[0][1][1] = -prices[0]; + dp[0][2][0] = 0; + dp[0][2][1] = Integer.MIN_VALUE; + + for (int i = 1; i < prices.length; i++) { + for (int j = 2; j >= 1; j--) { + // dp公式 + dp[i][j][0] = Math.max(dp[i - 1][j][0], dp[i - 1][j][1] + prices[i]); + dp[i][j][1] = Math.max(dp[i - 1][j][1], dp[i - 1][j - 1][0] - prices[i]); + } + } + + int res = 0; + for (int i = 1; i < 3; i++) { + res = Math.max(res, dp[prices.length - 1][i][0]); + } + return res; + } +} +``` + Python： From 4c3b4d8e5e45efa6b226521b4615aa8eb7742185 Mon Sep 17 00:00:00 2001 From: wzs <1014355013@qq.com> Date: Wed, 12 May 2021 23:23:55 +0800 Subject: [PATCH 4/6] =?UTF-8?q?=E6=B7=BB=E5=8A=A00188.=E4=B9=B0=E5=8D=96?= =?UTF-8?q?=E8=82=A1=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6=E6=9C=BA?= =?UTF-8?q?IV=E5=92=8CJava=E7=89=88=E6=9C=AC?= 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 | 43 ++++++++++++++++++- 1 file changed, 41 insertions(+), 2 deletions(-) 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 11c5805b..937aee3a 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 @@ -25,7 +25,7 @@ 输入：k = 2, prices = [3,2,6,5,0,3] 输出：7 解释：在第 2 天 (股票价格 = 2) 的时候买入，在第 3 天 (股票价格 = 6) 的时候卖出, 这笔交易所能获得利润 = 6-2 = 4。随后，在第 5 天 (股票价格 = 0) 的时候买入，在第 6 天 (股票价格 = 3) 的时候卖出, 这笔交易所能获得利润 = 3-0 = 3 。 -  + 提示： @@ -167,9 +167,48 @@ public: ## 其他语言版本 - Java： +```java +class Solution { //动态规划 + public int maxProfit(int k, int[] prices) { + if (prices == null || prices.length < 2 || k == 0) { + return 0; + } + + // [天数][交易次数][是否持有股票] + int[][][] dp = new int[prices.length][k + 1][2]; + + // bad case + dp[0][0][0] = 0; + dp[0][0][1] = Integer.MIN_VALUE; + dp[0][1][0] = 0; + dp[0][1][1] = -prices[0]; + // dp[0][j][0] 都均为0 + // dp[0][j][1] 异常值都取Integer.MIN_VALUE; + for (int i = 2; i < k + 1; i++) { + dp[0][i][0] = 0; + dp[0][i][1] = Integer.MIN_VALUE; + } + + for (int i = 1; i < prices.length; i++) { + for (int j = k; j >= 1; j--) { + // dp公式 + dp[i][j][0] = Math.max(dp[i - 1][j][0], dp[i - 1][j][1] + prices[i]); + dp[i][j][1] = Math.max(dp[i - 1][j][1], dp[i - 1][j - 1][0] - prices[i]); + } + } + + int res = 0; + for (int i = 1; i < k + 1; i++) { + res = Math.max(res, dp[prices.length - 1][i][0]); + } + + return res; + } +} +``` + Python： From cbc7efa1b2bc1080ceb027e8ef811ac6c403611e Mon Sep 17 00:00:00 2001 From: wzs <1014355013@qq.com> Date: Wed, 12 May 2021 23:24:54 +0800 Subject: [PATCH 5/6] =?UTF-8?q?=E6=B7=BB=E5=8A=A00309.=E6=9C=80=E4=BD=B3?= =?UTF-8?q?=E4=B9=B0=E5=8D=96=E8=82=A1=E7=A5=A8=E6=97=B6=E6=9C=BA=E5=90=AB?= =?UTF-8?q?=E5=86=B7=E5=86=BB=E6=9C=9F=E5=92=8CJava=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...09.最佳买卖股票时机含冷冻期.md | 26 ++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/problems/0309.最佳买卖股票时机含冷冻期.md b/problems/0309.最佳买卖股票时机含冷冻期.md index 15bba0b7..25f4cd8c 100644 --- a/problems/0309.最佳买卖股票时机含冷冻期.md +++ b/problems/0309.最佳买卖股票时机含冷冻期.md @@ -159,9 +159,33 @@ public: ## 其他语言版本 - Java： +```java +class Solution { + public int maxProfit(int[] prices) { + if (prices == null || prices.length < 2) { + return 0; + } + int[][] dp = new int[prices.length][2]; + + // bad case + dp[0][0] = 0; + dp[0][1] = -prices[0]; + dp[1][0] = Math.max(dp[0][0], dp[0][1] + prices[1]); + dp[1][1] = Math.max(dp[0][1], -prices[1]); + + for (int i = 2; i < prices.length; i++) { + // dp公式 + dp[i][0] = Math.max(dp[i - 1][0], dp[i - 1][1] + prices[i]); + dp[i][1] = Math.max(dp[i - 1][1], dp[i - 2][0] - prices[i]); + } + + return dp[prices.length - 1][0]; + } +} +``` + Python： From e476ac95872857c363a89203386b2156c3971d33 Mon Sep 17 00:00:00 2001 From: wzs <1014355013@qq.com> Date: Wed, 12 May 2021 23:26:17 +0800 Subject: [PATCH 6/6] =?UTF-8?q?=E6=B7=BB=E5=8A=A00714.=E4=B9=B0=E5=8D=96?= =?UTF-8?q?=E8=82=A1=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6=E6=9C=BA?= =?UTF-8?q?=E5=90=AB=E6=89=8B=E7=BB=AD=E8=B4=B9=E5=92=8CJava=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...买卖股票的最佳时机含手续费.md | 24 ++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/problems/0714.买卖股票的最佳时机含手续费.md b/problems/0714.买卖股票的最佳时机含手续费.md index 92697a64..6d0e6a5e 100644 --- a/problems/0714.买卖股票的最佳时机含手续费.md +++ b/problems/0714.买卖股票的最佳时机含手续费.md @@ -154,9 +154,31 @@ public: ## 其他语言版本 - Java： +```java +class Solution { // 动态规划 + public int maxProfit(int[] prices, int fee) { + if (prices == null || prices.length < 2) { + return 0; + } + + int[][] dp = new int[prices.length][2]; + + // bad case + dp[0][0] = 0; + dp[0][1] = -prices[0]; + + for (int i = 1; i < prices.length; i++) { + dp[i][0] = Math.max(dp[i - 1][0], dp[i - 1][1] + prices[i] - fee); + dp[i][1] = Math.max(dp[i - 1][1], dp[i - 1][0] - prices[i]); + } + + return dp[prices.length - 1][0]; + } +} +``` + Python：