Minimize the number by changing at most K digits
Given a number N, the task is to minimize the number by changing at most K digits. Note that the number should not contain any leading zeros.
Examples:
Input: N = 91945, K = 3
Output: 10045Input: N = 1, K = 0
Output: 1
Approach:
- Replace the first digit with 1 if its not already 1 and update K accordingly.
- Now for the rest of the digits, replace the next K – 1 non-zero digits with a 0.
Below is the implementation of the above approach:
C++
// C++ implementation of the approach #include <iostream> using namespace std; // Function to return the minimized number string minNum(string num, int k) { // Total digits in the number int len = num.length(); // If the string is empty or there // are no operations to perform if (len == 0 || k == 0) return num; // "0" is a valid number if (len == 1) return "0" ; // If the first digit is not already 1 then // update it to 1 and decrement k if (num[0] != '1' ) { num[0] = '1' ; k--; } int i = 1; // While there are operations left // and the number can still be updated while (k > 0 && i < len) { // If the current digit is not already 0 // then update it to 0 and decrement k if (num[i] != '0' ) { num[i] = '0' ; k--; } i++; } // Return the minimised number return num; } // Driver code int main() { string num = "91945" ; int k = 3; cout << minNum(num, k); return 0; } |
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Java
// Java implementation of the approach class GFG { // Function to return the minimized number static String minNum( char num[], int k) { // Total digits in the number int len = num.length; // If the string is empty or there // are no operations to perform if (len == 0 || k == 0 ) { String num_str = new String(num); return num_str; } // "0" is a valid number if (len == 1 ) return "0" ; // If the first digit is not already 1 then // update it to 1 and decrement k if (num[ 0 ] != '1' ) { num[ 0 ] = '1' ; k--; } int i = 1 ; // While there are operations left // and the number can still be updated while (k > 0 && i < len) { // If the current digit is not already 0 // then update it to 0 and decrement k if (num[i] != '0' ) { num[i] = '0' ; k--; } i++; } String num_str = new String(num); // Return the minimised number return num_str; } // Driver code public static void main(String args[]) { String num = "91945" ; int k = 3 ; System.out.println(minNum(num.toCharArray(), k)); } } // This code is contributed by AnkitRai01 |
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Python3
# Python 3 implementation of the approach # Function to return the minimized number def minNum(num, k) : # Total digits in the number len_ = len (num) # If the string is empty or there # are no operations to perform if len_ = = 0 or k = = 0 : return num # "0" is a valid number if len_ = = 1 : return "0" # If the first digit is not already 1 then # update it to 1 and decrement k if num[ 0 ] ! = '1' : num = '1' + num[ 1 :] k - = 1 i = 1 # While there are operations left # and the number can still be updated while k > 0 and i < len_ : # If the current digit is not already 0 # then update it to 0 and decrement k if num[i] ! = '0' : num = num[:i] + '0' + num[i + 1 :] k - = 1 i + = 1 # Return the minimised number return num # Driver code num = "91945" k = 3 print (minNum(num, k)) # This code is contributed by divyamohan123 |
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C#
// C# implementation of the approach using System; class GFG { // Function to return the minimized number static String minNum( char []num, int k) { // Total digits in the number int len = num.Length; // If the string is empty or there // are no operations to perform if (len == 0 || k == 0) { return String.Join( "" , num); } // "0" is a valid number if (len == 1) return "0" ; // If the first digit is not already 1 then // update it to 1 and decrement k if (num[0] != '1' ) { num[0] = '1' ; k--; } int i = 1; // While there are operations left // and the number can still be updated while (k > 0 && i < len) { // If the current digit is not already 0 // then update it to 0 and decrement k if (num[i] != '0' ) { num[i] = '0' ; k--; } i++; } // Return the minimised number return String.Join( "" , num); } // Driver code public static void Main(String []args) { String num = "91945" ; int k = 3; Console.WriteLine(minNum(num.ToCharArray(), k)); } } // This code is contributed by 29AjayKumar |
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Output:
10045
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