Recursion Array

int maxSubArraySum(int a[], int size) 
{ 
int max_so_far = 0, max_ending_here = 0; 
for (int i = 0; i < size; i++) 
{ 
	max_ending_here = max_ending_here + a[i]; 
	if (max_ending_here < 0) 
		max_ending_here = 0; 

	/* Do not compare for all elements. Compare only 
		when max_ending_here > 0 */
	else if (max_so_far < max_ending_here) 
		max_so_far = max_ending_here; 
} 
return max_so_far; 
} 

const arrSum = arr => arr.reduce((a,b) => a + b, 0)
// arrSum([20, 10, 5, 10]) -> 45

function palindrome(str) {
    const alphanumericOnly = str
        // 1) Lowercase the input
        .toLowerCase()
        // 2) Strip out non-alphanumeric characters
        .match(/[a-z0-9]/g);
        
    // 3) return string === reversedString
    return alphanumericOnly.join('') ===
        alphanumericOnly.reverse().join('');
}



palindrome("eye");

class Solution{
    //Function to count the frequency of all elements from 1 to N in the array.
    public static void frequencyCount(int arr[], int N, int P)
    {
        //Decreasing all elements by 1 so that the elements
        //become in range from 0 to n-1.
        int maxi = Math.max(P,N);
        int count[] = new int[maxi+1];
        Arrays.fill(count, 0);
        for(int i=0;i<N;i++){
            count[arr[i]]++; 
        }
        
        for(int i=0;i<N;i++){
            arr[i] = count[i+1];
        }
    }
}

import java.io.*;
import java.util.*;

class GFG 
{
	static int maxCuts(int n, int a, int b, int c)
	{
		if(n == 0) return 0;
		if(n < 0)  return -1;

		int res = Math.max(maxCuts(n-a, a, b, c), 
		          Math.max(maxCuts(n-b, a, b, c), 
		          maxCuts(n-c, a, b, c)));

		if(res == -1)
			return -1;

		return res + 1; 
	}
  
    public static void main(String [] args) 
    {
    	int n = 5, a = 2, b = 1, c = 5;
    	
    	System.out.println(maxCuts(n, a, b, c));
    }
}

import java.util.ArrayDeque;
import java.util.Arrays;
import java.util.Queue;

class Pair {
    int x, y;

    public Pair(int x, int y) {
        this.x = x;
        this.y = y;
    }
}

class FloodFill
{
    // Below arrays details all 8 possible movements
    private static final int[] row = { -1, -1, -1, 0, 0, 1, 1, 1 };
    private static final int[] col = { -1, 0, 1, -1, 1, -1, 0, 1 };

    // check if it is possible to go to pixel (x, y) from
    // current pixel. The function returns false if the pixel
    // has different color or it is not a valid pixel
    public static boolean isSafe(char[][] M, int m, int n,
                                int x, int y, char target)
    {
        return x >= 0 && x < m && y >= 0 && y < n
                && M[x][y] == target;
    }

    // Flood fill using BFS
    public static void floodfill(char[][] M, int x, int y, char replacement)
    {
        int m = M.length;
        int n = M[0].length;

        // create a queue and enqueue starting pixel
        Queue<Pair> q = new ArrayDeque<>();
        q.add(new Pair(x, y));

        // get target color
        char target = M[x][y];

        // run till queue is not empty
        while (!q.isEmpty())
        {
            // pop front node from queue and process it
            Pair node = q.poll();

            // (x, y) represents current pixel
            x = node.x;
            y = node.y;

            // replace current pixel color with that of replacement
            M[x][y] = replacement;

            // process all 8 adjacent pixels of current pixel and
            // enqueue each valid pixel
            for (int k = 0; k < row.length; k++)
            {
                // if adjacent pixel at position (x + row[k], y + col[k]) is
                // a valid pixel and have same color as that of current pixel
                if (isSafe(M, m, n, x + row[k], y + col[k], target))
                {
                    // enqueue adjacent pixel
                    q.add(new Pair(x + row[k], y + col[k]));
                }
            }
        }
    }

    public static void main(String[] args)
    {
        // matrix showing portion of the screen having different colors
        char[][] M = {
            "YYYGGGGGGG".toCharArray(),
            "YYYYYYGXXX".toCharArray(),
            "GGGGGGGXXX".toCharArray(),
            "WWWWWGGGGX".toCharArray(),
            "WRRRRRGXXX".toCharArray(),
            "WWWRRGGXXX".toCharArray(),
            "WBWRRRRRRX".toCharArray(),
            "WBBBBRRXXX".toCharArray(),
            "WBBXBBBBXX".toCharArray(),
            "WBBXXXXXXX".toCharArray()
        };

        // start node
        int x = 3, y = 9;   // target color = "X"

        // replacement color
        char replacement = 'C';

        // replace target color with replacement color
        floodfill(M, x, y, replacement);

        // print the colors after replacement
        for (int i = 0; i < M.length; i++) {
            System.out.println(Arrays.toString(M[i]));
        }
    }
}

# Python3 implementation of the approach 

# Function to sort the array such that 
# negative values do not get affected 
def sortArray(a, n): 

	# Store all non-negative values 
	ans=[] 
	for i in range(n): 
		if (a[i] >= 0): 
			ans.append(a[i]) 

	# Sort non-negative values 
	ans = sorted(ans) 

	j = 0
	for i in range(n): 

		# If current element is non-negative then 
		# update it such that all the 
		# non-negative values are sorted 
		if (a[i] >= 0): 
			a[i] = ans[j] 
			j += 1

	# Print the sorted array 
	for i in range(n): 
		print(a[i],end = " ") 


# Driver code 

arr = [2, -6, -3, 8, 4, 1] 

n = len(arr) 

sortArray(arr, n) 

class Solution
{
    // String array to store keypad characters
    static String hash[] = {"", "", "abc", "def", "ghi", "jkl", "mno", "pqrs", "tuv", "wxyz"};
    
    //Function to find list of all words possible by pressing given numbers.
    static ArrayList <String> possibleWords(int a[], int N)
    {
        String str = "";
        for(int i = 0; i < N; i++)
        str += a[i];
        ArrayList<String> res = possibleWordsUtil(str);
        //arranging all possible strings lexicographically.
        Collections.sort(res); 
        return res;
                    
    }
    
    //recursive function to return all possible words that can
    //be obtained by pressing input numbers.  
    static ArrayList<String> possibleWordsUtil(String str)
    {
        //if str is empty 
        if (str.length() == 0) { 
            ArrayList<String> baseRes = new ArrayList<>(); 
            baseRes.add(""); 
  
            //returning a list containing empty string.
            return baseRes; 
        } 
        
        //storing first character of str
        char ch = str.charAt(0); 
        //storing rest of the characters of str 
        String restStr = str.substring(1); 
  
        //getting all the combination by calling function recursively.
        ArrayList<String> prevRes = possibleWordsUtil(restStr); 
        ArrayList<String> Res = new ArrayList<>(); 
      
        String code = hash[ch - '0']; 
  
        for (String val : prevRes) { 
  
            for (int i = 0; i < code.length(); i++) { 
                Res.add(code.charAt(i) + val); 
            } 
        } 
        //returning the list.
        return Res; 
    }
}

const arrMin = arr => Math.min(...arr);
// arrMin([20, 10, 5, 10]) -> 5

const arrMax = arr => Math.max(...arr);
// arrMax([20, 10, 5, 10]) -> 20

const arrAvg = arr => arr.reduce((a,b) => a + b, 0) / arr.length
// arrAvg([20, 10, 5, 10]) -> 11.25

const compact = arr => arr.filter(Boolean);

compact([0, 1, false, 2, '', 3, 'a', 'e' * 23, NaN, 's', 34]); 

var str = "How are you doing today?";

var res = str.split(" ");
 

let cars = [
  {
    "color": "purple",
    "type": "minivan",
    "registration": new Date('2017-01-03'),
    "capacity": 7
  },
  {
    "color": "red",
    "type": "station wagon",
    "registration": new Date('2018-03-03'),
    "capacity": 5
  },
  {
    ...
  },
  ...
]

// add to the beginning 
const car = {
  "color": "red",
  "type": "cabrio",
  "registration": new Date('2016-05-02'),
  "capacity": 2
}
cars.unshift(car);

// add to the end
const car = {
 "color": "red",
 "type": "cabrio",
 "registration": new Date('2016-05-02'),
 "capacity": 2
}
cars.push(car);

// add somewhere in the middle 
Array.splice(
  {index where to start},
  {how many items to remove},
  {items to add}
);

// place the car after the 4th element in the array
let car = {
  "color": "red",
  "type": "cabrio",
  "registration": new Date('2016-05-02'),
  "capacity": 2
}
cars.splice(4, 0, car);

import java.util.*;

public class Main {

  public static void main(String[] args) {
    // Write your code here

    int[] arr = {1,2,7,4,5};

    boolean ans = sorted(arr, 0);

    System.out.print(ans);

  }

  public static boolean sorted(int[] arr,int index) {
    if(index == arr.length-1){
      return true;
    }

    return arr[index]<arr[index+1] && sorted(arr, index+1);

  }
}