Every business depends on customer's loyalty. The repeat business from customer is one of the cornerstone for business profitability. So it is important to know the reason of customers leaving a business. Customers going away is known as customer churn. By looking at the past trends we can judge what factors influence customer churn and how to predict if a particular customer will go away from the business. In this article we will use ML algorithm to study the past trends in customer churn and then judge which customers are likely to churn.Data PreparationAs an example will consider the Telecom ... Read More

Frauds are really in many transactions. We can apply machine learning algorithms to lies the past data and predict the possibility of a transaction being a fraud transaction. In our example we will take credit card transactions, analyse the data, create the features and labels and finally apply one of the ML algorithms to judge the nature of transaction as being fraud or not. Then we will find out the accuracy, precision as well as f-score of the model we are chosen.Preparing the DataWe in this step we read the source data, study the variables present in it and have ... Read More

Python allows XML data to be read and processed through its inbuilt module called expat. It is a non-validating XML parser. it creates an XML parser object and captures the attributes of its objects into various handler functions. In the below example we will see how the various handler functions can help us read the XML file as well as give the attribute values as the output data. This generated data can be used for the processing.Exampleimport xml.parsers.expat # Capture the first element def first_element(tag, attrs):    print ('first element:', tag, attrs) # Capture the last element def last_element(tag):   ... Read More

Census data is the source of information collected by the government to understand the population and its characteristics. It consists of details such as age, gender, education, and housing. This helps the government in understanding the current scenario as well as planning for the future. In this article, we are going to learn how to analyze the census data in Python. Python, with its libraries like pandas, numpy, and matplotlib, is widely used for analyzing census data. Analyzing Census Data Here, we are going to use the sample data that consists of the census data stored in ... Read More

In this problem, we are given a prefix expression. Our task is to print the infix conversion of the given expression.Prefix expression is those expressions which have operators before the operands.Example: +AB.Infix expressions are those expressions which have operators between the operands.Example: A+BInfix expression are information for human understanding, but the computer does computations on prefix or postfix expressions (generally postfix).Let’s take an example to understand the problemInput: prefix : /+LM/NX Output: infix : (L+M) / (N/X)To solve this problem, we will be using the stack data structure. We will traverse the prefix expression in reverse order of the expression. ... Read More

In this problem, we are given a prefix expression. Our task is to print the postfix conversion of the given expression.Prefix expression is those expressions which have operators before the operands.Example: +AB.Postfix expressions are those expressions which have operators after operands in the expressions.Example: AB/The conversion of prefix to postfix should not involve the conversion to infix.Let’s take an example to understand the problem, Input: /+XY+NM Output: XY+NM+/ Explanation: infix -> (X+Y)/(N+M)To solve this problem, we will first traverse the whole postfix expression in an reverse order. And we will be using the stack data structure for our processing. And do ... Read More

In this problem, we are given string str containing only a and b and an integer N such that a string is created by appending str n times. Our task is to print the total number of substring in which the count of a’s is more than the count of b.Let’s take an example to understand the problemInput: aab 2 Output: 9 Explanation: created string is aabaab. Substrings with count(a) > count(b) : ‘a’ , ‘aa’, ‘aab’, ‘aaba’, ‘aabaa’, ‘aabaab’, ‘aba’, ‘baa’, ‘abaa’.To solve this problem, we will have to check if the string contains the required prefix subsets. Here, ... Read More

In this problem, we are given the inorder and postorder traversal of a binary tree. Our task is to print the postorder traversal of the tree.Let’s take an example to understand the problemInput:inorder: 16 7 21 12 1 5 9 postorder: 16 21 7 1 9 5 12 Output: preorder: 12 7 16 21 5 1 9 Explanation: the binary tree is :To solve this problem, a simple solution could be creating a tree using the given traversals and then finding the preorder traversal of the tree. But this method will be more complex for the system.A more effective solution ... Read More

In this problem, we are given a binary tree and a node value. Our task is to print the preorder predecessor of the node.Binary Tree is a special type of tree in which each root node can have maximum 2 child nodes.Preorder Traversal is a way to traverse nodes of the tree. In this we will first traverse root node then left child and then the right child.Preorder predecessor node is the node that comes before the node in the preorder traversal of the node.Let’s take an example to understand the problemInput: 1 Output: 9To solve this problem, a navie approach will ... Read More

In this problem, we are given a binary tree and a node value. Our task is to print the preorder successor of the node.Binary Tree is a special type of tree in which each root node can have maximum 2 child nodes.Preorder Traversal is a way to traverse nodes of the tree. In this we will first traverse root node then left child and then the right child.Preorder successor node is the node that comes next to the node in the preorder traversal of the node.Let’s take an example to understand the problemInput: 9 Output 0 Explanation: the preorder traversal ... Read More