May 27, 2022 · May 9, 2022 · May 10, 2022 · May 10, 2022 · May 10, 2022 · May 11, 2022
diff --git a/problems/0019.删除链表的倒数第N个节点.md b/problems/0019.删除链表的倒数第N个节点.md
diff --git a/problems/0027.移除元素.md b/problems/0027.移除元素.md
diff --git a/problems/0416.分割等和子集.md b/problems/0416.分割等和子集.md
diff --git a/problems/0701.二叉搜索树中的插入操作.md b/problems/0701.二叉搜索树中的插入操作.md
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
diff --git a/problems/背包理论基础01背包-2.md b/problems/背包理论基础01背包-2.md
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Expand Up		@@ -39,7 +39,7 @@

		分为如下几步:

	* 首先这里我推荐大家使用虚拟头结点,这样方面处理删除实际头结点的逻辑,如果虚拟头结点不清楚,可以看这篇: [链表:听说用虚拟头节点会方便很多?](https://programmercarl.com/0203.移除链表元素.html)
	* 首先这里我推荐大家使用虚拟头结点,这样方便处理删除实际头结点的逻辑,如果虚拟头结点不清楚,可以看这篇: [链表:听说用虚拟头节点会方便很多?](https://programmercarl.com/0203.移除链表元素.html)

		* 定义fast指针和slow指针,初始值为虚拟头结点,如图:

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Expand Up		@@ -81,7 +81,7 @@ public:

		双指针法(快慢指针法)在数组和链表的操作中是非常常见的,很多考察数组、链表、字符串等操作的面试题,都使用双指针法。

	后序都会一一介绍到,本题代码如下:
	后续都会一一介绍到,本题代码如下:

		```CPP
		// 时间复杂度:O(n)
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Expand Up		@@ -416,6 +416,7 @@ var canPartition = function(nums) {
		};
		```


		C:
		二维dp:
		```c
Expand Down Expand Up		@@ -517,6 +518,62 @@ bool canPartition(int* nums, int numsSize){
		}
		```

	TypeScript:

	> 一维数组,简洁

	```typescript
	function canPartition(nums: number[]): boolean {
	const sum: number = nums.reduce((pre, cur) => pre + cur);
	if (sum % 2 === 1) return false;
	const bagSize: number = sum / 2;
	const goodsNum: number = nums.length;
	const dp: number[] = new Array(bagSize + 1).fill(0);
	for (let i = 0; i < goodsNum; i++) {
	for (let j = bagSize; j >= nums[i]; j--) {
	dp[j] = Math.max(dp[j], dp[j - nums[i]] + nums[i]);
	}
	}
	return dp[bagSize] === bagSize;
	};
	```

	> 二维数组,易懂

	```typescript
	function canPartition(nums: number[]): boolean {
	/**
	weightArr = nums;
	valueArr = nums;
	bagSize = sum / 2; (sum为nums各元素总和);
	按照0-1背包处理
	*/
	const sum: number = nums.reduce((pre, cur) => pre + cur);
	if (sum % 2 === 1) return false;
	const bagSize: number = sum / 2;
	const weightArr: number[] = nums;
	const valueArr: number[] = nums;
	const goodsNum: number = weightArr.length;
	const dp: number[][] = new Array(goodsNum)
	.fill(0)
	.map(_ => new Array(bagSize + 1).fill(0));
	for (let i = weightArr[0]; i <= bagSize; i++) {
	dp[0][i] = valueArr[0];
	}
	for (let i = 1; i < goodsNum; i++) {
	for (let j = 0; j <= bagSize; j++) {
	if (j < weightArr[i]) {
	dp[i][j] = dp[i - 1][j];
	} else {
	dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - weightArr[i]] + valueArr[i]);
	}
	}
	}
	return dp[goodsNum - 1][bagSize] === bagSize;
	};
	```




		-----------------------
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Expand Up		@@ -279,7 +279,7 @@ class Solution:
		root.right = self.insertIntoBST(root.right, val)

		# 返回更新后的以当前root为根节点的新树
	return roo
	return root
		```

		递归法 - 无返回值
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Expand Up		@@ -432,6 +432,7 @@ function test () {
		test();
		```


		### C
		```c
		#include <stdio.h>
Expand Down Expand Up		@@ -478,5 +479,48 @@ int main(int argc, char* argv[]) {
		}
		```


	### TypeScript

	```typescript
	function testWeightBagProblem(
	weight: number[],
	value: number[],
	size: number
	): number {
	/**
	* dp[i][j]: 前i个物品,背包容量为j,能获得的最大价值
	* dp[0][*]: u=weight[0],u之前为0,u之后(含u)为value[0]
	* dp[*][0]: 0
	* ...
	* dp[i][j]: max(dp[i-1][j], dp[i-1][j-weight[i]]+value[i]);
	*/
	const goodsNum: number = weight.length;
	const dp: number[][] = new Array(goodsNum)
	.fill(0)
	.map((_) => new Array(size + 1).fill(0));
	for (let i = weight[0]; i <= size; i++) {
	dp[0][i] = value[0];
	}
	for (let i = 1; i < goodsNum; i++) {
	for (let j = 1; j <= size; j++) {
	if (j < weight[i]) {
	dp[i][j] = dp[i - 1][j];
	} else {
	dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - weight[i]] + value[i]);
	}
	}
	}
	return dp[goodsNum - 1][size];
	}
	// test
	const weight = [1, 3, 4];
	const value = [15, 20, 30];
	const size = 4;
	console.log(testWeightBagProblem(weight, value, size));
	```



		-----------------------
		<div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>
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Expand Up		@@ -351,6 +351,31 @@ int main(int argc, char** argv) {
		}
		```

	### TypeScript

	```typescript
	function testWeightBagProblem(
	weight: number[],
	value: number[],
	size: number
	): number {
	const goodsNum: number = weight.length;
	const dp: number[] = new Array(size + 1).fill(0);
	for (let i = 0; i < goodsNum; i++) {
	for (let j = size; j >= weight[i]; j--) {
	dp[j] = Math.max(dp[j], dp[j - weight[i]] + value[i]);
	}
	}
	return dp[size];
	}
	const weight = [1, 3, 4];
	const value = [15, 20, 30];
	const size = 4;
	console.log(testWeightBagProblem(weight, value, size));

	```



		-----------------------
		<div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>