Programming Articles - Page 2071 of 3363

Suppose we have a linked list like l1 -> l2 -> l3 -> l4 -> … -> l(n-1) -> ln. We have to rearrange this list into the form l1 -> ln -> l2 -> l(n - 1) -> … and so on. Here the constraint is that, we cannot modify the values in the list nodes, only the node itself may be changed. So for example, if the list is like [1, 2, 3, 4, 5], then the output will be [1, 5, 2, 4, 3]To solve this, we will follow these steps −Define a method called reverse to ... Read More

Suppose we have a binary tree; we have to flatten it into linked list in place. So if the tree is like −The output tree will be −To solve this, we will follow these steps −ser prev := nullDefine a recursive function solve(), that will take root as input.if root is null, then returnsolve(right of root)solve(left of root)right of root := prev, left of root := nullprev := rootLet us see the following implementation to get better understanding −Example Live Demo#include using namespace std; class TreeNode{    public:    int val;    TreeNode *left, *right;    TreeNode(int data){     ... Read More

Suppose we have a binary tree; we have to find the Zigzag level order traversal. So for the first row, scan from left to right, then right to left from the second row, then again left to right and so on. So if the tree is like −The traversal sequence will be [[3], [20, 9], [15, 7]]To solve this, we will follow these steps −if the tree is empty, return empty listqueue := make a queue and insert root into the queue, create two empty lists res and res2, and set flag as Truewhile queue is not emptymake a list ... Read More

In this article, we will learn to use the readNBytes() method of InputStream in Java 9. We will get to know the InputStream Class with its methods as readNBytes() is a method of this class. After that, we will learn about the readNBytes() method with its syntax and when to use this method, along with an example. InputStream Class The Java InputStream class is the superclass of all classes representing an input stream of bytes. Every subclass of InputStream always needs to introduce a method to return the next byte on request. The following are some of the common methods of ... Read More

In this article we will see how to create a list of lists which contain string data types. The inner list themselves or of string data type and they may contain numeric or strings as their elements.Using strip and splitWe use these two methods which will first separate out the lists and then convert each element of the list to a string.Example Live Demolist1 = [ '[0, 1, 2, 3]', '["Mon", "Tue", "Wed", "Thu"]' ] print ("The given list is : " + str(list1)) print("") # using strip() + split() result = [k.strip("[]").split(", ") for k in list1] print ("Converting list ... Read More

The cmp() is part of the python standard library which compares two integers. The result of comparison is -1 if the first integer is smaller than second and 1 if the first integer is greater than the second. If both are equal the result of cmp() is zero.Below example illustrates different scenario showing the use of cmp() method.Example Live Demodef cmp(x, y):    return (x > y) - (x < y) #x>y x = 5 y = 3 print("The cmp value for x>y is : ",cmp(x, y),"") #xy is : 1 The cmp value for x

In this article we consider a dictionary where the values are presented as lists. Then we consider clearing those values from the lists. We have two approaches here. One is to use the clear methods and another is to designate empty values to each key using list comprehension.Example Live Demox1 = {"Apple" : [4, 6, 9, 2], "Grape" : [7, 8, 2, 1], "Orange" : [3, 6, 2, 4]} x2 = {"mango" : [4, 6, 9, 2], "pineapple" : [7, 8, 2, 1], "cherry" : [3, 6, 2, 4]} print("The given input is : " + str(x1)) # using loop + ... Read More

In this article we will see how to find the frequency of each character in a given string. Then see if two or more characters have the same frequency in the given string or not. We will accomplish this in two steps. In the first program we will just find out the frequency of each character.Frequency of each characterHere we find the frequency of each character in the given input screen. We declare a empty dictionary and then add each character as a string. We also assign keys to each of the character to create the key-value pair needed by ... Read More

During analysis of data sets we may come across situations where we have to deal with empty dictionaries. In tis article we will see how to check if a dictionary is empty or not.Using ifThe if condition evaluates to true if the dictionary has elements. Otherwise it evaluates to false. So in the below program we will just check the emptiness of a dictionary using only the if condition.Example Live Demodict1 = {1:"Mon", 2:"Tue", 3:"Wed"} dict2 = {} # Given dictionaries print("The original dictionary : " ,(dict1)) print("The original dictionary : " ,(dict2)) # Check if dictionary is empty if dict1: ... Read More

In python data analysis, we sometime face a situation where we need to compare a given number with a list containing many values. In this article we need to fins if a given number is less than each of the values present in a given list. We are going to achieve it using the following two ways.Using for loopWe iterate through the given list and compare the given value with each of the values in the list. Once all values from the list are compared and the comparison condition holds good in each of the step, we print out the ... Read More