From f93ad90c69237b706dc3d0c82b2ba598275e5c9e Mon Sep 17 00:00:00 2001 From: ironartisan Date: Thu, 26 Aug 2021 20:04:48 +0800 Subject: [PATCH 1/4] =?UTF-8?q?=E6=B7=BB=E5=8A=A00455.=E5=88=86=E5=8F=91?= =?UTF-8?q?=E9=A5=BC=E5=B9=B2java=E4=BB=A3=E7=A0=81?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0455.分发饼干.md | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/problems/0455.分发饼干.md b/problems/0455.分发饼干.md index b6fa4a98..f377b99e 100644 --- a/problems/0455.分发饼干.md +++ b/problems/0455.分发饼干.md @@ -117,6 +117,7 @@ public: Java： ```java class Solution { + // 思路1：优先考虑饼干，小饼干先喂饱小胃口 public int findContentChildren(int[] g, int[] s) { Arrays.sort(g); Arrays.sort(s); @@ -132,6 +133,25 @@ class Solution { } } ``` +```java +class Solution { + // 思路2：优先考虑胃口，先喂饱大胃口 + public int findContentChildren(int[] g, int[] s) { + Arrays.sort(g); + Arrays.sort(s); + int count = 0; + int start = s.length - 1; + // 遍历胃口 + for (int index = g.length - 1; index >= 0; index--) { + if(start >= 0 && g[index] <= s[start]) { + start--; + count++; + } + } + return count; + } +} +``` Python： ```python3 From 1b915d57bf54c46f070b2852f12407e5ea2d6492 Mon Sep 17 00:00:00 2001 From: ironartisan Date: Thu, 26 Aug 2021 20:14:24 +0800 Subject: [PATCH 2/4] =?UTF-8?q?=E6=B7=BB=E5=8A=A00455.=E5=88=86=E5=8F=91?= =?UTF-8?q?=E9=A5=BC=E5=B9=B2Python3=E4=BB=A3=E7=A0=81?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0455.分发饼干.md | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/problems/0455.分发饼干.md b/problems/0455.分发饼干.md index f377b99e..1e1c4afe 100644 --- a/problems/0455.分发饼干.md +++ b/problems/0455.分发饼干.md @@ -156,6 +156,7 @@ class Solution { Python： ```python3 class Solution: + # 思路1：优先考虑胃饼干 def findContentChildren(self, g: List[int], s: List[int]) -> int: g.sort() s.sort() @@ -165,6 +166,20 @@ class Solution: res += 1 return res ``` +```python +class Solution: + # 思路2：优先考虑胃口 + def findContentChildren(self, g: List[int], s: List[int]) -> int: + g.sort() + s.sort() + start, count = len(s) - 1, 0 + for index in range(len(g) - 1, -1, -1): # 先喂饱大胃口 + if start >= 0 and g[index] <= s[start]: + start -= 1 + count += 1 + return count +``` + Go： ```golang //排序后，局部最优 From d6531b0f2b9699031087ad660ea6744e5c36508a Mon Sep 17 00:00:00 2001 From: ironartisan Date: Fri, 27 Aug 2021 21:25:07 +0800 Subject: [PATCH 3/4] =?UTF-8?q?=E6=B7=BB=E5=8A=A00541=E7=BF=BB=E8=BD=AC?= =?UTF-8?q?=E5=AD=97=E7=AC=A6=E4=B8=B2java=E4=BB=A3=E7=A0=81?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0541.反转字符串II.md | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/problems/0541.反转字符串II.md b/problems/0541.反转字符串II.md index 02713c65..914fba23 100644 --- a/problems/0541.反转字符串II.md +++ b/problems/0541.反转字符串II.md @@ -152,7 +152,35 @@ class Solution { } } ``` +```java +// 解法3 +class Solution { + public String reverseStr(String s, int k) { + char[] ch = s.toCharArray(); + // 1. 每隔 2k 个字符的前 k 个字符进行反转 + for (int i = 0; i< ch.length; i += 2 * k) { + // 2. 剩余字符小于 2k 但大于或等于 k 个，则反转前 k 个字符 + if (i + k <= ch.length) { + reverse(ch, i, i + k -1); + continue; + } + // 3. 剩余字符少于 k 个，则将剩余字符全部反转 + reverse(ch, i, ch.length - 1); + } + return new String(ch); + } + // 定义翻转函数 + public void reverse(char[] ch, int i, int j) { + for (; i < j; i++, j--) { + char temp = ch[i]; + ch[i] = ch[j]; + ch[j] = temp; + } + + } +} +``` Python： ```python class Solution: From 48ab781c4e6c3d8c6ddf9610f5adda300884b291 Mon Sep 17 00:00:00 2001 From: ironartisan Date: Sat, 28 Aug 2021 09:39:16 +0800 Subject: [PATCH 4/4] =?UTF-8?q?=E4=BC=98=E5=8C=960122.=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=20Java=E4=BB=A3=E7=A0=81?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0122.买卖股票的最佳时机II.md | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) 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 ff1b6d4a..29aa5b83 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 @@ -139,17 +139,11 @@ Java： // 贪心思路 class Solution { public int maxProfit(int[] prices) { - int sum = 0; - int profit = 0; - int buy = prices[0]; + int result = 0; for (int i = 1; i < prices.length; i++) { - profit = prices[i] - buy; - if (profit > 0) { - sum += profit; - } - buy = prices[i]; + result += Math.max(prices[i] - prices[i - 1], 0); } - return sum; + return result; } } ```