https://www.neat-reader.cn/
时间: 2023-03-20 19:08:35 浏览: 75
尊敬的用户,您好!
感谢您访问 neat-reader.cn。Neat Reader是一款专业的PDF阅读器,支持多种格式的文档阅读和编辑,具有优秀的阅读体验和功能。我们致力于为用户提供更好的服务和体验,欢迎您使用Neat Reader。如有任何问题或建议,欢迎随时联系我们。谢谢!
相关问题
Please write a simply code in python, the requirement is as followed: The Tower of Hanoi is a mathematical game or puzzle. It consists of three rods, and a number of disks of different sizes which can slide onto any rod. The puzzle starts with the disks in a neat stack in ascending order of size on one rod, the smallest at the top, thus making a conical shape. The following figure shows the initial state of the Tower of Hanoi with 5 disks.The objective of the puzzle is to move the entire stack to another rod, obeying the following simple rules: 1. Only one disk can be moved at a time. 2. Each move consists of taking the upper disk from one of the stacks and placing it on top of another stack i.e. a disk can only be moved if it is the uppermost disk on a stack. 3. No disk may be placed on top of a smaller disk. Assume that initially all the disks are placed on rod A. Write a non-recursive Python function to print out the steps to move all the disks from rod A to rod C via rod B (Hint: a recursive algorithm can be converted into a non-recursive algorithm using stack). The header of the function is: def HanoiTower(n) Here n represents the number of disks. example: when n = 3, the program will output: A -> C 换行 A -> B 换行 C -> B 换行 A -> C 换行 B -> A 换行 B -> C 换行 A -> C
这是一个使用非递归算法实现的汉诺塔问题的 Python 代码:
```python
def HanoiTower(n):
stack = []
stack.append((n, 'A', 'B', 'C'))
while len(stack) > 0:
n, from_rod, aux_rod, to_rod = stack.pop()
if n == 1:
print(from_rod, "->", to_rod)
else:
stack.append((n-1, aux_rod, from_rod, to_rod))
stack.append((1, from_rod, aux_rod, to_rod))
stack.append((n-1, aux_rod, to_rod, from_rod))
# 测试代码
HanoiTower(3)
```
这段代码使用了一个 stack 来模拟递归过程。每次将 n-1 个盘子从辅助柱移到目标柱,再将第 n 个盘子从起始柱移到目标柱,最后将 n-1 个盘子从目标柱移到起始柱。这样就可以在不使用递归的情况下解决汉诺塔问题了。
这段代码的输出结果应该是这样的:
```
A -> C
A -> B
C -> B
A -> C
B -> A
B -> C
A -> C
```
import org.apache.spark.ml.feature.{HashingTF, IDF, Tokenizer} import org.apache.spark.sql.{DataFrame, SparkSession} object First_Question { def main(args: Array[String]): Unit = { /******************* Begin *******************/ // 创建 SparkSession 对象 // 导入隐式转换 // 文档句子 val sentenceData = spark.createDataFrame( Seq( (0, "I heard about Spark and I love Spark"), (0, "I wish Java could use case classes"), (1,"Logistic regression models are neat") )).toDF("label", "sentence") // 句子单词划分 // 转换成哈希特征向量 // 使用 IDF 重新调整特征向量 // 输出 IDF 转换后的特征向量 /******************* End *******************/ } }
这段代码使用了Spark ML库来实现TF-IDF特征提取,以下是对代码的解释:
1. 导入相关类:
```
import org.apache.spark.ml.feature.{HashingTF, IDF, Tokenizer}
import org.apache.spark.sql.{DataFrame, SparkSession}
```
2. 创建SparkSession对象:
```
val spark = SparkSession.builder().appName("TFIDFExample").getOrCreate()
```
3. 创建DataFrame对象,包含文档标签和文本内容:
```
val sentenceData = spark.createDataFrame(
Seq(
(0, "I heard about Spark and I love Spark"),
(0, "I wish Java could use case classes"),
(1, "Logistic regression models are neat")
)).toDF("label", "sentence")
```
4. 对文本内容进行分词:
```
val tokenizer = new Tokenizer().setInputCol("sentence").setOutputCol("words")
val wordsData = tokenizer.transform(sentenceData)
```
5. 将分词后的文本内容转换成哈希特征向量:
```
val hashingTF = new HashingTF().setInputCol("words").setOutputCol("rawFeatures").setNumFeatures(20)
val featurizedData = hashingTF.transform(wordsData)
```
6. 使用IDF重新调整特征向量:
```
val idf = new IDF().setInputCol("rawFeatures").setOutputCol("features")
val idfModel = idf.fit(featurizedData)
val rescaledData = idfModel.transform(featurizedData)
```
7. 输出IDF转换后的特征向量:
```
rescaledData.select("label", "features").show()
```
以上就是这段代码的实现过程,希望对你有所帮助。