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In Java 9, few static methods: stream(), or(), and ifPresentOrElse() have added to Optional class. The introduction of an Optional class solves the null pointer exception.Optional.or() method returns an Optional describing the value if a value is present, otherwise returns an Optional produced by the supplying function. Syntaxpublic Optional or(Supplier
In this article we will be discussing how we can quickly merge two sorted arrays using std::merge() function in C++ STL.So, before solving the problem let's first discuss the std::merge() in C++ STL.What is std::merge()?std::merge() function is an inbuilt function in C++ STL, which is defined in the header file. merge() is used to merge two sorted ranges or series. This function combines two sorted ranges to make one single sorted range. All the elements are compared using less than operator (
In this problem, we are given a number. Our task is to find the XOR of the count of 0s and 1s in the binary representation of the number.Let’s take an example to understand the problem, Inputn = 9Output0Explanationbinary = 1001 Count of 0s = 2 Count of 1s = 2 2 ^ 2 = 0To solve this problem, we will first convert the number of its binary equivalent and then iterating over each bit of the number, count 0s, and 1s and then find XOR of the count of 0s and count of 1s.Program to illustrate the above solution, ... Read More
Here, we have to create a strcmp (string compare) function that compares two string but ignores cases of the characters of the string. The function will return -1 if string1 < string2, 0 if string1 = string2, 1 if string1 > string2.Let’s take an example to understand the problem, Inputstring1 = “Hello” , string2 = “hello”Output0To create our own strcmp function that ignores cases while comparing the strings. We will iterate through all characters of both the strings, if characters at ith index are the same i.e. string1[i] == string2[i], continue. If string1[i] > string2[i], return 1. If string1[i] < ... Read More
In this problem, we are given two integers x and y. Our task is to create a function that will be equivalent to pow(x, y) using an iterative approach that will complete the task in time complexity of 0(Log y).Let’s take a few examples to understand the problem, Inputx = 7 , y = 3Output343The iterative function for pow(x, y) will iterate and update the result for odd values of y multiplying it by x and update x to x2 at every iteration.Program to show the implementation of the solutionExample Live Demo#include using namespace std; void calcPower(int x, unsigned int ... Read More
A program to reverse digits of a number will interchange the position of the digits and reverse there order.Let’s suppose be a number abcde the reverse will be edcba.Let’s take an example to understand the problem, Inputn = 786521Output125687To reverse digits of the number, we will take each digit of the number from MSB(unit digit) and add it to reverse number variable, after this divide the original number by 10 and the reverse_number is multiplied by 10. This will be done until the number becomes 0.This repetitive process can be accomplished by two methods, iteration, and recursion, we will create ... Read More
In this problem, we are given an unsigned integer n. Our task is to create a program that returns the number which is generated by reversing all the bits of the number.Let’s take an example to understand the problem, Inputn = 1Output2147483648Explanationbinary of 1 is 000...0001, the reverse is 100...0000.To solve this problem, we simple solution will be using a simple formula. We will loop through the binary of the number. And find the position of the set bit in the number lets say it i. The result will be calculated using the formula, ((total_number_of_bits) - 1) - iProgram to ... Read More
Here, we need to write a program that is used to check if the given number is a multiple of 3 or not.A general solution is a trivial solution, adding all the digits of the number and if the sum is a multiple of three then the number is divisible by 3 else not. But this solution is not the most efficient one.An efficient solution will be using the bit count in the binary representation of the number. If the difference between the count of set bits at odd position and the count of set bits at even position is ... Read More
In this problem, we are given two trees. Our task is to write a code to check whether the two trees are identical or not.Two trees are said to be identical if elements of the arrays have the same value and orientation.ExampleAs both of the trees have the same values and position of elements both trees are identical.To check if two trees are identical, we will go from node node to each node of the and check for their equality step by step and if at any point to nodes are not equal return -1, denoting the tree are not ... Read More
In competitive programming, the most important thing is an effective code. Optimized and faster code is important and can make a difference in the ranks of the programmer.To write an effective c/c++ code in competitive programming, here are some effective tools for writing c/c++ code efficiently, First, let’s recall some basic terms, Template is writing code that does not depend on a particular type.Macro is a named code fragment.Vectors are like automatically resizable dynamic arrays that update size with insertion and deletion of the element.Now, let’s see some basic updates in code that can make in increasing efficiency of code, ... Read More