Found 33676 Articles for Programming

How to find the position of NA in an R vector?

Nizamuddin Siddiqui
Updated on 05-Feb-2021 08:20:00

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When we have NA’s/missing values in an R vector then we want to replace those NA’s and for this purpose we might be needing the position of those values. These positions will be helpful especially in situations when we want to manually replace the missing values. The replacement can be done by using which function with is.na.Example1 Live Demox1

How to check if a matrix is invertible or not in R?

Nizamuddin Siddiqui
Updated on 05-Feb-2021 08:15:19

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If the matrix is singular then it is not invertible and if it is non−singular then it is invertible. Therefore, we can check if a matrix is singular or not. We can use is.singular.matrix function of matrixcalc for this purpose. For example, if we have a matrix called M then to check whether it is invertible or not, we can use is.singular.matrix(M).Example1Loading matrixcalc package and creating a matrix −library(matrixcalc) M1

How to remove repeated column names in a data.table object in R?

Nizamuddin Siddiqui
Updated on 05-Feb-2021 08:00:04

487 Views

In data analysis, we sometimes deal with duplicated data or just the representation of the data with same name. One such situation is column names are same for two columns in a data.table object. For this purpose, we can make use of which function with the combination of duplicated function and set the output of that duplicate to NULL to remove the repeated column names.Example1Loading data.table package and creating a data.table object −library(data.table) x1

Tim Sort Algorithm in C++

Dev Prakash Sharma
Updated on 05-Feb-2021 12:59:11

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The Timsort is a stable sorting algorithm that uses the idea of merge sort and insertion sort. It can also be called as a hybrid algorithm of insertion and merge sort. It is widely used in Java, Python, C, and C++ inbuilt sort algorithms. The idea behind this algorithm is to sort small chunks using insertion sort and then merge all the big chunks using the merge function of the merge sort algorithm.WorkingIn this algorithm, the array is divided into small chunks. The chunks are known as RUN. Each RUN is taken and sorted using the insertion sort technique. After ... Read More

What are Delannoy Numbers? Write a program in C++ to find the Delannoy number

Dev Prakash Sharma
Updated on 05-Feb-2021 12:58:37

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Delannoy Numbers − A Delannoy number D describes the number of paths from the southwest corner(0, 0) to northeast corner(a, b) in a rectangular grid using only allowed steps east ( →), northeast ( ↗ ) and north ( ↑ ).Thus, we can say that a recurrence relation is, D(a, b) = D(a-1, b) + D(a, b-1) + D(a-1, b-1) where D(0, 0)=1.For example, the Delannoy number D(3, 3) equals 63.Algorithm to find the Delannoy NumberTake two coordinates (a, b) as Input.An Integer function generateDelannoy(int a, int b) which takes coordinates ‘a’ and ‘b’ as input.In the base case, we ... Read More

Validate IPv6 address using ReGex patterns in C++

Dev Prakash Sharma
Updated on 05-Feb-2021 12:57:54

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Given an IP Address, the task is to validate this IP address and check whether it is IPv6 or not with the help of ReGex(Regular Expression). If the IP Address is valid then print “IPv6 Address” otherwise print “Not”.A valid IPv4 address is an IP in the form "XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX" where each Xi digit is a hexadecimal digit. For example, Input-1 −IP= “3001:0da8:82a3:0:0:8B2E:0270:7224”Output −“Not”Explanation − This is not a valid IPv6 address, return “Not”.Input-2 −IP= “2001:0db8:85a3:0000:0000:8a2e:0370:7334”Output −“IPv6”Explanation − This is a valid IPv6 Address, return “IPv6”.Approach to solve this problemTo check whether the given IP address is IPv6 or not, we ... Read More

Validate IPv4 address using ReGex patterns in C++

Dev Prakash Sharma
Updated on 05-Feb-2021 12:57:29

2K+ Views

Given an IP Address, the task is to validate this IP address and check whether it is IPv4 or not with the help of ReGex(Regular Expression). If the IP Address is valid then print “IPv4 Address” otherwise print “Not”.A valid IPv4 address is an IP in the form "X1.X2.X3.X4" where 0

Valid Sudoku in C++

Dev Prakash Sharma
Updated on 05-Feb-2021 12:57:03

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Let’s suppose we’ve given a 9×9 matrix called a Sudoku. The task is to check whether the given Sudoku Pattern is valid or not.In general, a Sudoku board look like this, Rules of Sudoku −Every row contains a number in the range 1-9Every column contains numbers in the range 1-9.Each block of 3×3 contains unique numbers in it.A particular row cannot have the same number.A particular column cannot have the same number.For ExampleInput-1 −sudoku[]=    [["3", "5", ".", ".", "2", ".", ".", ".", "."]    , ["7", ".", ".", "1", "6", "5", ".", ".", "."]    , [".", "9", "8", ... Read More

Update the bit in the given position or Index of a number using C++

Dev Prakash Sharma
Updated on 05-Feb-2021 12:56:21

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In the given problem, we have to update the bit of the given index of a number. To update the number, we can use Bit Manipulation operation on a given number. For example, Input-1 −N= 25 bit= 1 position= 2Output −29Explanation − Since the given input 25 can be written in binary as ‘11001’ whereas the position index is ‘2’ and the bit is ‘1’. After replacing the digits at the given position the output will be ‘11101’ which is equivalent to ‘29’.Approach to solve this problemIn the given position or index of a number, the task is to update ... Read More

static_assert in C++

Dev Prakash Sharma
Updated on 05-Feb-2021 12:55:01

408 Views

static_assert is a function which is useful for programmers to print the error in the screen after compiling the program without messing up with the output too much.Earlier in C++11 and C++14, static_assert had different functionality which means we have to write our own message while defining the static_assert. However, In C++ 17 static_assert can be invoked without passing the message.It is compatible with other asserts libraries functions like BOOST_STATIC_ASSERT as well.Syntax{    auto __range= For-range-Intializer;    auto __begin= begin-expression;    auto __end= end-expression;    for(; __begin!= __end; ++__begin){       range-declaration= *__begin;       statement    } ... Read More

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