From 50ed10475df9c62dae9e149a867a6f083a0dde04 Mon Sep 17 00:00:00 2001 From: jianghongcheng <35664721+jianghongcheng@users.noreply.github.com> Date: Mon, 12 Jun 2023 01:59:52 -0500 Subject: [PATCH 1/5] =?UTF-8?q?Update=200746.=E4=BD=BF=E7=94=A8=E6=9C=80?= =?UTF-8?q?=E5=B0=8F=E8=8A=B1=E8=B4=B9=E7=88=AC=E6=A5=BC=E6=A2=AF.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0746.使用最小花费爬楼梯.md | 28 ++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/problems/0746.使用最小花费爬楼梯.md b/problems/0746.使用最小花费爬楼梯.md index cd5e40e6..9eaaa4e9 100644 --- a/problems/0746.使用最小花费爬楼梯.md +++ b/problems/0746.使用最小花费爬楼梯.md @@ -282,7 +282,35 @@ class Solution: return dp1 # 返回到达楼顶的最小花费 ``` +动态规划（版本三） +```python +class Solution: + def minCostClimbingStairs(self, cost: List[int]) -> int: + dp = [0] * len(cost) + dp[0] = cost[0] # 第一步有花费 + dp[1] = cost[1] + for i in range(2, len(cost)): + dp[i] = min(dp[i - 1], dp[i - 2]) + cost[i] + # 注意最后一步可以理解为不用花费，所以取倒数第一步，第二步的最少值 + return min(dp[-1], dp[-2]) + +``` +动态规划（版本四） + +```python +class Solution: + def minCostClimbingStairs(self, cost: List[int]) -> int: + n = len(cost) + prev_1 = cost[0] # 前一步的最小花费 + prev_2 = cost[1] # 前两步的最小花费 + for i in range(2, n): + current = min(prev_1, prev_2) + cost[i] # 当前位置的最小花费 + prev_1, prev_2 = prev_2, current # 更新前一步和前两步的最小花费 + return min(prev_1, prev_2) # 最后一步可以理解为不用花费，取倒数第一步和第二步的最少值 + + +``` ### Go ```Go func minCostClimbingStairs(cost []int) int { From 5527410f890ecfccdb017ce5aa5fc902328ab922 Mon Sep 17 00:00:00 2001 From: jianghongcheng <35664721+jianghongcheng@users.noreply.github.com> Date: Mon, 12 Jun 2023 02:59:20 -0500 Subject: [PATCH 2/5] =?UTF-8?q?Update=200063.=E4=B8=8D=E5=90=8C=E8=B7=AF?= =?UTF-8?q?=E5=BE=84II.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0063.不同路径II.md | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/problems/0063.不同路径II.md b/problems/0063.不同路径II.md index 7b5b44f0..cb305b41 100644 --- a/problems/0063.不同路径II.md +++ b/problems/0063.不同路径II.md @@ -397,7 +397,39 @@ class Solution: ``` +动态规划（版本五） +```python +class Solution: + def uniquePathsWithObstacles(self, obstacleGrid): + if obstacleGrid[0][0] == 1: + return 0 + + m, n = len(obstacleGrid), len(obstacleGrid[0]) + + dp = [0] * n # 创建一个一维列表用于存储路径数 + + # 初始化第一行的路径数 + for j in range(n): + if obstacleGrid[0][j] == 1: + break + dp[j] = 1 + + # 计算其他行的路径数 + for i in range(1, m): + if obstacleGrid[i][0] == 1: + dp[0] = 0 + for j in range(1, n): + if obstacleGrid[i][j] == 1: + dp[j] = 0 + continue + + dp[j] += dp[j - 1] + + return dp[-1] # 返回最后一个元素，即终点的路径数 + + +``` ### Go ```go From 072eb2aa471f025afdb690e57a23c0932b5a4697 Mon Sep 17 00:00:00 2001 From: jianghongcheng <35664721+jianghongcheng@users.noreply.github.com> Date: Mon, 12 Jun 2023 03:32:07 -0500 Subject: [PATCH 3/5] =?UTF-8?q?Update=200343.=E6=95=B4=E6=95=B0=E6=8B=86?= =?UTF-8?q?=E5=88=86.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0343.整数拆分.md | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/problems/0343.整数拆分.md b/problems/0343.整数拆分.md index d70641db..3ff8dedb 100644 --- a/problems/0343.整数拆分.md +++ b/problems/0343.整数拆分.md @@ -262,10 +262,11 @@ class Solution: # 计算切割点j和剩余部分(i-j)的乘积，并与之前的结果进行比较取较大值 - dp[i] = max(dp[i], max((i - j) * j, dp[i - j] * j)) + dp[i] = max(dp[i], (i - j) * j, dp[i - j] * j) return dp[n] # 返回最终的计算结果 + ``` 动态规划（版本二） ```python From 35a87bd56c87a642cd28f119be3814fe0e1bf63f Mon Sep 17 00:00:00 2001 From: jianghongcheng <35664721+jianghongcheng@users.noreply.github.com> Date: Fri, 23 Jun 2023 12:14:15 -0500 Subject: [PATCH 4/5] =?UTF-8?q?Update=200416.=E5=88=86=E5=89=B2=E7=AD=89?= =?UTF-8?q?=E5=92=8C=E5=AD=90=E9=9B=86.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0416.分割等和子集.md | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/problems/0416.分割等和子集.md b/problems/0416.分割等和子集.md index 1f129312..a1158d7e 100644 --- a/problems/0416.分割等和子集.md +++ b/problems/0416.分割等和子集.md @@ -324,6 +324,21 @@ class Solution: return True return False +``` + +卡哥版(简化版) +```python +class Solution: + def canPartition(self, nums: List[int]) -> bool: + if sum(nums) % 2 != 0: + return False + target = sum(nums) // 2 + dp = [0] * (target + 1) + for num in nums: + for j in range(target, num-1, -1): + dp[j] = max(dp[j], dp[j-num] + num) + return dp[-1] == target + ``` 二维DP版 ```python From 71980306bf6f653145c0c0f0313a02bd8dd1a77f Mon Sep 17 00:00:00 2001 From: jianghongcheng <35664721+jianghongcheng@users.noreply.github.com> Date: Fri, 23 Jun 2023 12:58:24 -0500 Subject: [PATCH 5/5] =?UTF-8?q?Update=201049.=E6=9C=80=E5=90=8E=E4=B8=80?= =?UTF-8?q?=E5=9D=97=E7=9F=B3=E5=A4=B4=E7=9A=84=E9=87=8D=E9=87=8FII.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/1049.最后一块石头的重量II.md | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/problems/1049.最后一块石头的重量II.md b/problems/1049.最后一块石头的重量II.md index a978b802..932029ab 100644 --- a/problems/1049.最后一块石头的重量II.md +++ b/problems/1049.最后一块石头的重量II.md @@ -238,6 +238,21 @@ class Solution: return total_sum - dp[target] - dp[target] +``` + +卡哥版（简化版） +```python +class Solution: + def lastStoneWeightII(self, stones): + total_sum = sum(stones) + target = total_sum // 2 + dp = [0] * (target + 1) + for stone in stones: + for j in range(target, stone - 1, -1): + dp[j] = max(dp[j], dp[j - stone] + stone) + return total_sum - 2* dp[-1] + + ``` 二维DP版 ```python