Contents

## How do you find a number in an array which is repeated?

JAVA

- public class DuplicateElement {
- public static void main(String[] args) {
- //Initialize array.
- int [] arr = new int [] {1, 2, 3, 4, 2, 7, 8, 8, 3};
- System.out.println(“Duplicate elements in given array: “);
- //Searches for duplicate element.
- for(int i = 0; i < arr.length; i++) {
- for(int j = i + 1; j < arr.length; j++) {

### How do you find out how many times an integer appears in an array?

6 Answers

- Keep a variable for the total count.
- Loop through the array and check if current value is the same as the one you’re looking for, if it is, increment the total count by one.
- After the loop, total count contains the number of times the number you were looking for is in the array.

**Can you make an array of integers?**

One-Dimensional Arrays : The element type determines the data type of each element that comprises the array. Like an array of integers, we can also create an array of other primitive data types like char, float, double, etc. or user-defined data types (objects of a class).

**How do you check if an array is a permutation of another?**

Efficient Approach:

- Traverse the given array and insert every element in the set data structure.
- Also, find the maximum element in the array.
- After traversal of the array, check if the size of the set is equal to N.
- If the size of the set if equal to N then the array represents a permutation else it doesn’t.

## How do you find missing elements in an array?

Approach: The length of the array is n-1. So the sum of all n elements, i.e sum of numbers from 1 to n can be calculated using the formula n*(n+1)/2. Now find the sum of all the elements in the array and subtract it from the sum of first n natural numbers, it will be the value of the missing element.

### How do you count occurrences?

Select a cell next to the list you want to count the occurrence of a word, and then type this formula =COUNTIF(A2:A12,”Judy”) into it, then press Enter, and you can get the number of appearances of this word.

**How do I count in Numpy?**

numpy. count() in Python

- Parameters:
- arr : array-like or string to be searched.
- substring : substring to search for.
- start, end : [int, optional] Range to search in.

**Can you have a double array?**

An array is a sequence of values; the values in the array are called elements. You can make an array of int s, double s, or any other type, but all the values in an array must have the same type. The second makes values refer to an array of double , where the number of elements in values depends on the value of size .

## How do you return an array?

How to return an array in Java

- import java.util.Arrays;
- public class ReturnArrayExample1.
- {
- public static void main(String args[])
- {
- int[] a=numbers(); //obtain the array.
- for (int i = 0; i < a.length; i++) //for loop to print the array.
- System.out.print( a[i]+ ” “);

### How do you Permute an array?

12 Answers. You take first element of an array (k=0) and exchange it with any element (i) of the array. Then you recursively apply permutation on array starting with second element. This way you get all permutations starting with i-th element.

**How do you implement two queues in a single array?**

A simple way to implement k queues is to divide the array in k slots of size n/k each, and fix the slots for different queues, i.e., use arr[0] to arr[n/k-1] for the first queue, and arr[n/k] to arr[2n/k-1] for queue2 where arr[] is the array to be used to implement two queues and size of array be n.