// C++ program to print all n-digit numbers such that // the absolute difference between the sum of digits at // even and odd positions is 1 #include    using namespace std; // Recursive function to generate numbers void findNDigitNumsUtil(int pos int n int num  int evenSum int oddSum  vector<int> &res) {  // If number is formed  if (pos == n) {  // Check absolute difference condition  if (abs(evenSum - oddSum) == 1) {  res.push_back(num);  }  return;  }  // Digits to consider at current position  for (int d = 0; d <= 9; d++) {  // Skip leading 0  if (pos == 0 && d == 0) {  continue;  }  // If position is even (0-based) add to evenSum  if (pos % 2 == 0) {  findNDigitNumsUtil(pos + 1 n num * 10 + d  evenSum + d oddSum res);  }  // If position is odd add to oddSum  else {  findNDigitNumsUtil(pos + 1 n num * 10 + d  evenSum oddSum + d res);  }  } } // Function to prepare and collect valid numbers vector<int> findNDigitNums(int n) {    vector<int> res;  findNDigitNumsUtil(0 n 0 0 0 res);    return res; } // Driver code int main() {  int n = 2;  vector<int> res = findNDigitNums(n);  for (int i = 0; i < res.size(); i++) {  cout << res[i] << ' ';  }  return 0; } 

// Java program to print all n-digit numbers such that // the absolute difference between the sum of digits at // even and odd positions is 1 import java.util.*; class GfG {  // Recursive function to generate numbers  static void findNDigitNumsUtil(int pos int n int num  int evenSum int oddSum  ArrayList<Integer> res) {  // If number is formed  if (pos == n) {  // Check absolute difference condition  if (Math.abs(evenSum - oddSum) == 1) {  res.add(num);  }  return;  }  // Digits to consider at current position  for (int d = 0; d <= 9; d++) {  // Skip leading 0  if (pos == 0 && d == 0) {  continue;  }  // If position is even (0-based) add to evenSum  if (pos % 2 == 0) {  findNDigitNumsUtil(pos + 1 n num * 10 + d  evenSum + d oddSum res);  }  // If position is odd add to oddSum  else {  findNDigitNumsUtil(pos + 1 n num * 10 + d  evenSum oddSum + d res);  }  }  }  // Function to prepare and collect valid numbers  static ArrayList<Integer> findNDigitNums(int n) {  ArrayList<Integer> res = new ArrayList<>();  findNDigitNumsUtil(0 n 0 0 0 res);  return res;  }  // Driver code  public static void main(String[] args) {  int n = 2;  ArrayList<Integer> res = findNDigitNums(n);  // Print all collected valid numbers  for (int i = 0; i < res.size(); i++) {  System.out.print(res.get(i) + ' ');  }  } } 

# Python program to print all n-digit numbers such that # the absolute difference between the sum of digits at # even and odd positions is 1 # Recursive function to generate numbers def findNDigitNumsUtil(pos n num evenSum oddSum res): # If number is formed if pos == n: # Check absolute difference condition if abs(evenSum - oddSum) == 1: res.append(num) return # Digits to consider at current position for d in range(10): # Skip leading 0 if pos == 0 and d == 0: continue # If position is even (0-based) add to evenSum if pos % 2 == 0: findNDigitNumsUtil(pos + 1 n num * 10 + d evenSum + d oddSum res) # If position is odd add to oddSum else: findNDigitNumsUtil(pos + 1 n num * 10 + d evenSum oddSum + d res) # Function to prepare and collect valid numbers def findNDigitNums(n): res = [] findNDigitNumsUtil(0 n 0 0 0 res) return res # Driver code if __name__ == '__main__': n = 2 res = findNDigitNums(n) # Print all collected valid numbers for i in range(len(res)): print(res[i] end=' ') 

// C# program to print all n-digit numbers such that // the absolute difference between the sum of digits at // even and odd positions is 1 using System; using System.Collections.Generic; class GfG {  // Recursive function to generate numbers  static void findNDigitNumsUtil(int pos int n int num  int evenSum int oddSum  List<int> res) {  // If number is formed  if (pos == n) {  // Check absolute difference condition  if (Math.Abs(evenSum - oddSum) == 1) {  res.Add(num);  }  return;  }  // Digits to consider at current position  for (int d = 0; d <= 9; d++) {  // Skip leading 0  if (pos == 0 && d == 0) {  continue;  }  // If position is even (0-based) add to evenSum  if (pos % 2 == 0) {  findNDigitNumsUtil(pos + 1 n num * 10 + d  evenSum + d oddSum res);  }  // If position is odd add to oddSum  else {  findNDigitNumsUtil(pos + 1 n num * 10 + d  evenSum oddSum + d res);  }  }  }  // Function to prepare and collect valid numbers  static List<int> findNDigitNums(int n) {  List<int> res = new List<int>();  findNDigitNumsUtil(0 n 0 0 0 res);  return res;  }  // Driver code  public static void Main(string[] args) {  int n = 2;  List<int> res = findNDigitNums(n);  // Print all collected valid numbers  for (int i = 0; i < res.Count; i++) {  Console.Write(res[i] + ' ');  }  } } 

// JavaScript program to print all n-digit numbers such that // the absolute difference between the sum of digits at // even and odd positions is 1 // Recursive function to generate numbers function findNDigitNumsUtil(pos n num evenSum oddSum res) {  // If number is formed  if (pos === n) {  // Check absolute difference condition  if (Math.abs(evenSum - oddSum) === 1) {  res.push(num);  }  return;  }  // Digits to consider at current position  for (let d = 0; d <= 9; d++) {  // Skip leading 0  if (pos === 0 && d === 0) {  continue;  }  // If position is even (0-based) add to evenSum  if (pos % 2 === 0) {  findNDigitNumsUtil(pos + 1 n num * 10 + d  evenSum + d oddSum res);  }  // If position is odd add to oddSum  else {  findNDigitNumsUtil(pos + 1 n num * 10 + d  evenSum oddSum + d res);  }  } } // Function to prepare and collect valid numbers function findNDigitNums(n) {  let res = [];  findNDigitNumsUtil(0 n 0 0 0 res);  return res; } // Driver code let n = 2; let res = findNDigitNums(n); // Print all collected valid numbers for (let i = 0; i < res.length; i++) {  process.stdout.write(res[i] + ' '); }