From e445b35d3691edf9ec0ab9fe30aaa6357b3c518a Mon Sep 17 00:00:00 2001 From: NevS <1173325467@qq.com> Date: Sun, 13 Jun 2021 01:55:37 +0800 Subject: [PATCH 1/9] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200239.=E6=BB=91?= =?UTF-8?q?=E5=8A=A8=E7=AA=97=E5=8F=A3=E6=9C=80=E5=A4=A7=E5=80=BC=20go?= =?UTF-8?q?=E7=89=88=20=EF=BC=88=E5=A2=9E=E5=8A=A0=E5=B0=81=E8=A3=85?= =?UTF-8?q?=E5=8D=95=E8=B0=83=E9=98=9F=E5=88=97=E8=A7=A3=E9=A2=98=E7=9A=84?= =?UTF-8?q?=E6=96=B9=E5=BC=8F=EF=BC=89?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 增加封装单调队列解题的方式 --- problems/0239.滑动窗口最大值.md | 60 ++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) diff --git a/problems/0239.滑动窗口最大值.md b/problems/0239.滑动窗口最大值.md index 47383a47..d108335b 100644 --- a/problems/0239.滑动窗口最大值.md +++ b/problems/0239.滑动窗口最大值.md @@ -332,6 +332,66 @@ func maxSlidingWindow(nums []int, k int) []int { ``` +```go +// 封装单调队列的方式解题 +type MyQueue struct { + queue []int +} + +func NewMyQueue() *MyQueue { + return &MyQueue{ + queue: make([]int, 0), + } +} + +func (m *MyQueue) Front() int { + return m.queue[0] +} + +func (m *MyQueue) Back() int { + return m.queue[len(m.queue)-1] +} + +func (m *MyQueue) Empty() bool { + return len(m.queue) == 0 +} + +func (m *MyQueue) Push(val int) { + for !m.Empty() && val > m.Back() { + m.queue = m.queue[:len(m.queue)-1] + } + m.queue = append(m.queue, val) +} + +func (m *MyQueue) Pop(val int) { + if !m.Empty() && val == m.Front() { + m.queue = m.queue[1:] + } +} + +func maxSlidingWindow(nums []int, k int) []int { + queue := NewMyQueue() + length := len(nums) + res := make([]int, 0) + // 先将前k个元素放入队列 + for i := 0; i < k; i++ { + queue.Push(nums[i]) + } + // 记录前k个元素的最大值 + res = append(res, queue.Front()) + + for i := k; i < length; i++ { + // 滑动窗口移除最前面的元素 + queue.Pop(nums[i-k]) + // 滑动窗口添加最后面的元素 + queue.Push(nums[i]) + // 记录最大值 + res = append(res, queue.Front()) + } + return res +} +``` + Javascript: ```javascript var maxSlidingWindow = function (nums, k) { From f5b8f8faeb8aa5965e534ba41ae8a2ea378d20b2 Mon Sep 17 00:00:00 2001 From: Kelvin Date: Sat, 12 Jun 2021 13:57:42 -0400 Subject: [PATCH 2/9] =?UTF-8?q?=E6=9B=B4=E6=96=B00343.=E6=95=B4=E6=95=B0?= =?UTF-8?q?=E6=8B=86=E5=88=86.md=20python3=E4=BB=A3=E7=A0=81=20-=20?= =?UTF-8?q?=E5=B0=8F=E6=94=B9=E5=8A=A8?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 根据讲解, dp[0], dp[1]不应该初始化. 如果 是for j in range(1, i): 递归方程就会需要dp[1]. 虽然也可以AC, 但是不合逻辑. --- problems/0343.整数拆分.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/problems/0343.整数拆分.md b/problems/0343.整数拆分.md index fefaa293..cf60575f 100644 --- a/problems/0343.整数拆分.md +++ b/problems/0343.整数拆分.md @@ -218,7 +218,7 @@ class Solution: # 假设对正整数 i 拆分出的第一个正整数是 j（1 <= j < i），则有以下两种方案： # 1) 将 i 拆分成 j 和 i−j 的和，且 i−j 不再拆分成多个正整数，此时的乘积是 j * (i-j) # 2) 将 i 拆分成 j 和 i−j 的和，且 i−j 继续拆分成多个正整数，此时的乘积是 j * dp[i-j] - for j in range(1, i): + for j in range(1, i - 1): dp[i] = max(dp[i], max(j * (i - j), j * dp[i - j])) return dp[n] ``` From 6673c56916ac17ed48b7a30bffe3d8912773a0b1 Mon Sep 17 00:00:00 2001 From: Kelvin Date: Sat, 12 Jun 2021 14:12:08 -0400 Subject: [PATCH 3/9] =?UTF-8?q?Update=20=E8=83=8C=E5=8C=85=E7=90=86?= =?UTF-8?q?=E8=AE=BA=E5=9F=BA=E7=A1=8001=E8=83=8C=E5=8C=85-1.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 修改indention. --- problems/背包理论基础01背包-1.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/problems/背包理论基础01背包-1.md b/problems/背包理论基础01背包-1.md index 852c489b..36544256 100644 --- a/problems/背包理论基础01背包-1.md +++ b/problems/背包理论基础01背包-1.md @@ -268,7 +268,7 @@ int main() { Java： ```java - public static void main(String[] args) { + public static void main(String[] args) { int[] weight = {1, 3, 4}; int[] value = {15, 20, 30}; int bagSize = 4; From 6a42937927f1e9c9c4925fa53332ddf4fe275d24 Mon Sep 17 00:00:00 2001 From: Kelvin Date: Sat, 12 Jun 2021 14:29:59 -0400 Subject: [PATCH 4/9] =?UTF-8?q?Update=20=E8=83=8C=E5=8C=85=E7=90=86?= =?UTF-8?q?=E8=AE=BA=E5=9F=BA=E7=A1=8001=E8=83=8C=E5=8C=85-2.md=20Python?= =?UTF-8?q?=E4=BB=A3=E7=A0=81?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 增加python部分代码. 测试结果: ``` [[0, 15, 15, 15, 15], [0, 15, 15, 20, 35], [0, 15, 15, 20, 35]] ``` 与题解一致. --- problems/背包理论基础01背包-1.md | 35 ++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/problems/背包理论基础01背包-1.md b/problems/背包理论基础01背包-1.md index 36544256..1269d9c1 100644 --- a/problems/背包理论基础01背包-1.md +++ b/problems/背包理论基础01背包-1.md @@ -307,6 +307,41 @@ Java： Python： +```python +def test_2_wei_bag_problem1(bag_size, weight, value) -> int: + rows, cols = len(weight), bag_size + 1 + dp = [[0 for _ in range(cols)] for _ in range(rows)] + res = 0 + + # 初始化dp数组. + for i in range(rows): + dp[i][0] = 0 + first_item_weight, first_item_value = weight[0], value[0] + for j in range(1, cols): + if first_item_weight <= j: + dp[0][j] = first_item_value + + # 更新dp数组: 先遍历物品, 再遍历背包. + for i in range(1, len(weight)): + cur_weight, cur_val = weight[i], value[i] + for j in range(1, cols): + if cur_weight > j: # 说明背包装不下当前物品. + dp[i][j] = dp[i - 1][j] # 所以不装当前物品. + else: + # 定义dp数组: dp[i][j] 前i个物品里，放进容量为j的背包，价值总和最大是多少。 + dp[i][j] = max(dp[i - 1][j], dp[i - 1][j - cur_weight]+ cur_val) + if dp[i][j] > res: + res = dp[i][j] + + print(dp) + + +if __name__ == "__main__": + bag_size = 4 + weight = [1, 3, 4] + value = [15, 20, 30] + test_2_wei_bag_problem1(bag_size, weight, value) +``` Go： From be2804f8740e5027354265d722d77e9e89e7fd0d Mon Sep 17 00:00:00 2001 From: Kelvin Date: Sat, 12 Jun 2021 14:30:30 -0400 Subject: [PATCH 5/9] =?UTF-8?q?Revert=20"Update=20=E8=83=8C=E5=8C=85?= =?UTF-8?q?=E7=90=86=E8=AE=BA=E5=9F=BA=E7=A1=8001=E8=83=8C=E5=8C=85-1.md"?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This reverts commit 6673c56916ac17ed48b7a30bffe3d8912773a0b1. --- problems/背包理论基础01背包-1.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/problems/背包理论基础01背包-1.md b/problems/背包理论基础01背包-1.md index 1269d9c1..f6646202 100644 --- a/problems/背包理论基础01背包-1.md +++ b/problems/背包理论基础01背包-1.md @@ -268,7 +268,7 @@ int main() { Java： ```java - public static void main(String[] args) { + public static void main(String[] args) { int[] weight = {1, 3, 4}; int[] value = {15, 20, 30}; int bagSize = 4; From 737b7c38e86a1365b99f4bcc4ef354c04dd44955 Mon Sep 17 00:00:00 2001 From: Kelvin Date: Sat, 12 Jun 2021 14:32:08 -0400 Subject: [PATCH 6/9] =?UTF-8?q?=E6=9B=B4=E6=94=B9=20=E8=83=8C=E5=8C=85?= =?UTF-8?q?=E7=90=86=E8=AE=BA=E5=9F=BA=E7=A1=8001=E8=83=8C=E5=8C=85-2.md?= =?UTF-8?q?=20Java=E6=A0=BC=E5=BC=8F?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 原版在github上显示不正确. --- problems/背包理论基础01背包-1.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/problems/背包理论基础01背包-1.md b/problems/背包理论基础01背包-1.md index f6646202..1269d9c1 100644 --- a/problems/背包理论基础01背包-1.md +++ b/problems/背包理论基础01背包-1.md @@ -268,7 +268,7 @@ int main() { Java： ```java - public static void main(String[] args) { + public static void main(String[] args) { int[] weight = {1, 3, 4}; int[] value = {15, 20, 30}; int bagSize = 4; From 3e506df04426ca8937f09f7a8e9ca9955d0d1c7e Mon Sep 17 00:00:00 2001 From: borninfreedom Date: Sun, 13 Jun 2021 10:56:21 +0800 Subject: [PATCH 7/9] =?UTF-8?q?update=E6=9C=89=E6=95=88=E7=9A=84=E5=AD=97?= =?UTF-8?q?=E6=AF=8D=E5=BC=82=E4=BD=8D=E8=AF=8D=EF=BC=8Cpython=E4=BB=A3?= =?UTF-8?q?=E7=A0=81=E6=B7=BB=E5=8A=A0=E4=BA=86=E6=9B=B4pythonic=E7=9A=84?= =?UTF-8?q?=E5=86=99=E6=B3=95?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0242.有效的字母异位词.md | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/problems/0242.有效的字母异位词.md b/problems/0242.有效的字母异位词.md index ba942f70..c3e73730 100644 --- a/problems/0242.有效的字母异位词.md +++ b/problems/0242.有效的字母异位词.md @@ -130,7 +130,27 @@ class Solution: return True ``` +Python写法二： + +```python +class Solution: + def isAnagram(self, s: str, t: str) -> bool: + from collections import defaultdict + + s_dict=defaultdict(int) + t_dict=defaultdict(int) + + for x in s: + s_dict[x]+=1 + + for x in t: + t_dict[x]+=1 + + return s_dict==t_dict +``` + Go： + ```go func isAnagram(s string, t string) bool { if len(s)!=len(t){ From 0d3b8de51227c0c55ace89aa249e0a25377a62be Mon Sep 17 00:00:00 2001 From: borninfreedom Date: Sun, 13 Jun 2021 10:58:05 +0800 Subject: [PATCH 8/9] =?UTF-8?q?=E6=9B=B4=E6=96=B0=E4=BB=A3=E7=A0=81?= =?UTF-8?q?=E8=A7=84=E8=8C=83?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0242.有效的字母异位词.md | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/problems/0242.有效的字母异位词.md b/problems/0242.有效的字母异位词.md index c3e73730..1956253a 100644 --- a/problems/0242.有效的字母异位词.md +++ b/problems/0242.有效的字母异位词.md @@ -137,16 +137,16 @@ class Solution: def isAnagram(self, s: str, t: str) -> bool: from collections import defaultdict - s_dict=defaultdict(int) - t_dict=defaultdict(int) + s_dict = defaultdict(int) + t_dict = defaultdict(int) for x in s: - s_dict[x]+=1 + s_dict[x] += 1 for x in t: - t_dict[x]+=1 + t_dict[x] += 1 - return s_dict==t_dict + return s_dict == t_dict ``` Go： From 4993e9ff6bfab26473eeb9b99f07ae544f0afca3 Mon Sep 17 00:00:00 2001 From: borninfreedom Date: Sun, 13 Jun 2021 11:14:21 +0800 Subject: [PATCH 9/9] =?UTF-8?q?=E6=9C=89=E6=95=88=E7=9A=84=E5=AD=97?= =?UTF-8?q?=E6=AF=8D=E5=BC=82=E4=BD=8D=E8=AF=8D=E6=B7=BB=E5=8A=A0=E4=B8=80?= =?UTF-8?q?=E4=BA=9B=E8=AF=B4=E6=98=8E?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0242.有效的字母异位词.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/problems/0242.有效的字母异位词.md b/problems/0242.有效的字母异位词.md index 1956253a..93bba44c 100644 --- a/problems/0242.有效的字母异位词.md +++ b/problems/0242.有效的字母异位词.md @@ -130,7 +130,7 @@ class Solution: return True ``` -Python写法二： +Python写法二（没有使用数组作为哈希表，只是介绍defaultdict这样一种解题思路）： ```python class Solution: