Given a positive integer N consisting only two types of digits 6 and 9, the task is to generate the minimum number possible by reversing at most one digit, that is 9 becomes 6 or vice versa.
Examples:
Input : 9996
Output : 6996
Explanation :
Changing the first digit results in 6996.
Changing the second digit results in 9696.
Changing the third digit results in 9966.
Changing the fourth digit results in 9999.
Hence, the minimum number among all possibilities is 6996.
Input : 6696
Output : 6666
Explanation :
Changing the first digit results in 9696.
Changing the second digit results in 6996.
Changing the third digit results in 6666.
Changing the fourth digit results in 6699.
Hence, the minimum number among all possibilities is 6666.
Approach:
In order to solve the problem, we need to follow the steps given below:
- First convert the given integer into a string.
- Traverse the string from left and change the very first occurrence of ‘9’ to ‘6’ and break out of the loop. If there is no occurrence of 9 in the initial string, then it is already the lowest number possible.
- Convert the final string back to the integer and print it.
Below is the implementation of the above approach:
C++
// C++ implementation to change at most// one digit to make the number// as minimum as possible#include <bits/stdc++.h>using namespace std;// Function to return the minimum // possible numberint minimum69Number(int num){ // Converting given number to string string s_num = to_string(num); // Traversing the string for (auto& c : s_num) { // change first 9 to 6 if (c == '9') { c = '6'; break; } } // Change the string back to the integer int result = stoi(s_num); // Return the final result return result;}// Driver codeint main(){ // Input number int n = 9996; int result = minimum69Number(n); // Print the result cout << result << endl;} |
Java
// Java implementation to change at most// one digit to make the number// as minimum as possibleclass GFG{// Function to return the minimum // possible numberstatic int minimum69Number(int num){ // Converting given number to String char []s_num = String.valueOf(num).toCharArray(); // Traversing the String for(int i = 0; i < s_num.length; i++) { // change first 9 to 6 if (s_num[i] == '9') { s_num[i] = '6'; break; } } // Change the String back to the integer int result = Integer.valueOf(String.valueOf(s_num)); // Return the final result return result;}// Driver codepublic static void main(String[] args){ // Input number int n = 9996; int result = minimum69Number(n); // Print the result System.out.print(result + "\n");}}// This code is contributed by 29AjayKumar |
Python3
# Python3 implementation to change at most# one digit to make the number# as minimum as possible# Function to return the minimum # possible numberdef minimum69Number(num): # Converting given number to string s_num = str(num) s_num = s_num.replace('9','6', 1) # Change the string back to the integer result = int(s_num) # Return the final result return result# Driver codeif __name__ == '__main__': # Input number n = 9996 result = minimum69Number(n) # Print the result print(result)# This code is contributed by Samarth |
C#
// C# implementation to change at most// one digit to make the number// as minimum as possibleusing System;class GFG{// Function to return the minimum // possible numberstatic int minimum69Number(int num){ // Converting given number to String char []s_num = String.Join("", num).ToCharArray(); // Traversing the String for(int i = 0; i < s_num.Length; i++) { // change first 9 to 6 if (s_num[i] == '9') { s_num[i] = '6'; break; } } // Change the String back to the integer int result = Int32.Parse(String.Join("", s_num)); // Return the readonly result return result;}// Driver codepublic static void Main(String[] args){ // Input number int n = 9996; int result = minimum69Number(n); // Print the result Console.Write(result + "\n");}}// This code is contributed by sapnasingh4991 |
Javascript
<script> // JavaScript implementation to change at most // one digit to make the number // as minimum as possible // Function to return the minimum // possible number function minimum69Number(num) { // Converting given number to string let s_num = (num.toString()).split(''); // Traversing the String for(let i = 0; i < s_num.length; i++) { // change first 9 to 6 if (s_num[i] == '9') { s_num[i] = '6'; break; } } // Change the String back to the integer let result = parseInt(s_num.join("")); // Return the final result return result; } // Driver code // Input number let n = 9996; let result = minimum69Number(n); // Print the result document.write(result); </script> |
Output:
6996
Time Complexity: O(n)
Auxiliary Space: O(1)
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