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Page 1156 of 2109
Sort an arrays of 0's, 1's and 2's using Java
Given an array of 0, 1 and 2 sort the element in an order such that all the zeros come first before 1 and all the 2’s in the end. We have to sort all the elements of the array in-place.We can solve this problem using DNF (Dutch National Flag) Sorting Algorithm. For example, Input-1 −arr[ ]= {2, 0, 0, 1, 2, 1 }Output −0 0 1 1 2 2Explanation − Sorting the given array of elements containing 0, 1 and 2 using the DNF Sorting Algorithm, it will print the output as {0, 0, 1, 1, 2, 2}.Input-2 −arr[ ...
Read MoreSquare of a sorted array in C++
In the given array of sorted integers, the task is to print the squares of every array element and print the array in sorted order. For example, Input-1 −arr[ ] = { -3, -1, 0, 1, 4, 6 };Output −{0, 1, 1, 9, 16, 36}Explanation − The squares of each of the elements of the given array [-3, -1, 0, 1, 4, 6 ] is [0, 1, 1, 9, 16, 36 ].Input-2 −arr[ ]= { 0, 1, 2, 8, 9 }Output −{0, 1, 4, 64, 81}Explanation − The squares of each of the elements of the given array [ 0, ...
Read MoreValid Sudoku in C++
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 MoreHow to find the position of NA in an R vector?
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.Example1x1
Read MoreHow to remove column names from an R data frame?
There are situations when we might want to remove column names such as we want to manually replace the existing column names by new names or we simply don’t want to use them if we are very much familiar with the column characteristics. To remove the columns names we can simply set them to NULL as shown in the below examples.Example1Consider the below data frame −set.seed(357) x1
Read MoreHow to convert matrix rows into a list in R?
Depending on our objective, a matrix rows might be needed to converted into a list that means each row will be an element of the list. This can be done by using the function as.list but firstly we need to convert the matrix into data frame after transposing. For example, if we have a matrix called M then it’s rows will be converted to a list using the command writtem below −as.list(data.frame(t(M)))Example1M1
Read MoreHow to find the mean of multiple columns based on a character column in R?
If we have a character column that means we are more likely to have duplicated values in that column hence finding the mean of numerical columns based on the values in character column cannot be done directly. For this purpose, we can use aggregate function as shown in the below examples.Example1Consider the below data frame −set.seed(214) x1
Read MoreHow to compare two dates in String format in Java?
The java.text.SimpleDateFormat class is used to format and parse a string to date and date to string.One of the constructors of this class accepts a String value representing the desired date format and creates SimpleDateFormat object. To parse/convert a string as a Date object Instantiate this class by passing desired format string.Parse the date string using the parse() method.The util.Date class represents a specific instant time This class provides various methods such as before(), after() and, equals() to compare two datesExampleOnce you create date objects from strings you can compare them using either of these methods as shown below −import java.text.ParseException; import ...
Read MoreHow to parse date sting to date in Java?
You can parse a string containing a data to date value using the following ways −The constructor SimpleDateFormat class accepts a String value representing the desired date format and creates this object. You can parse the date string using the parse() method of this class.The parse() method of the LocalDate class accepts a String value representing a date and returns a LocalDate object.The DateUtils provides utility to format date you can find it in apache.commons package. The parseDate() method of the DateUtils class accepts a format string and a date string as parameters and returns a Date object.The parse() method of ...
Read MoreHow to print date using GregorianCalendar class in Java?
The GregorianCalendar class supports standard calendars it supports Julian and Gregorian calendars you can create an object of GregorianCalendar using one of its constructors. Following are various examples demonstrating how to print date using this class −ExampleFollowing example creates GregorianCalander by passing year, month and date values as parameters to its constructor and prints the date −import java.util.Calendar; import java.util.GregorianCalendar; public class Test { public static void main(String args[]){ //Instantiating the GregorianCalendar GregorianCalendar cal = new GregorianCalendar(2018, 6, 27); System.out.println(cal); System.out.println("Date: "+cal.get(Calendar.DATE)); System.out.println("Month: "+cal.get(Calendar.MONTH)); ...
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