Find smallest permutation of given number
Given a long integer, return the smallest(magnitude) integer permutation of that number.
Examples:
Input : 5468001 Output : 1004568 Input : 5341 Output : 1345
Question Source : GE digital Interview Experience | Set 6
We have already discussed a solution in below post.
Smallest number by rearranging digits of a given number
In this post, a different approach is discussed.
Approach : As number is long, store the number as string, sort the string, if there is no leading zero, return this string, if there is any leading zero, swap first element of string with first non-zero element of string, and return the string.
Below is the implementation of above approach :
C++
// CPP program to find smallest // permutation of given number #include <bits/stdc++.h> using namespace std; // return the smallest number permutation string findSmallestPermutation(string s) { int len = s.length(); // sort the string sort(s.begin(), s.end()); // check for leading zero in string // if there are any leading zeroes, // swap the first zero with first non-zero number int i = 0; while (s[i] == '0' ) i++; swap(s[0], s[i]); return s; } // driver program int main() { // take number input in string string s = "5468001" ; string res = findSmallestPermutation(s); cout << res << endl; return 0; } |
Java
// Java program to find smallest // permutation of given number import java.util.Arrays; public class GFG { // return the smallest number permutation static char [] findSmallestPermutation(String s1) { // sort the string char s[] = s1.toCharArray(); Arrays.sort(s); // check for leading zero in string // if there are any leading zeroes, // swap the first zero with first non-zero // number int i = 0 ; while (s[i] == '0' ) i++; char temp = s[ 0 ]; s[ 0 ] = s[i]; s[i] = temp; return s; } // driver program public static void main(String args[]) { // take number input in string String s = "5468001" ; char res[] = findSmallestPermutation(s); System.out.println(res); } } // This code is contributed by Sumit Ghosh |
Python
# Python program to find smallest # permutation of given number # Sort function def sort_string(a): return ''.join( sorted (a)) # return the smallest number permutation def findSmallestPermutation(s): le = len (s) # sort the string s = sort_string(s) # check for leading zero in string # if there are any leading zeroes, # swap the first zero with first non-zero number i = 0 while (s[i] = = '0' ): i + = 1 a = list (s) a[ 0 ] = a[i] a[i] = '0' s = "".join(a) return s # driver program # take number input in string s = "5468001" res = findSmallestPermutation(s) print res # This code is contributed by Sachin Bisht |
C#
// C# program to find smallest // permutation of given number using System; public class GFG { // return the smallest number permutation static char [] findSmallestPermutation( string s1) { // sort the string char []s = s1.ToCharArray();; Array.Sort(s); // check for leading zero in string // if there are any leading zeroes, // swap the first zero with first non-zero // number int i = 0; while (s[i] == '0' ) i++; char temp = s[0]; s[0] = s[i]; s[i] = temp; return s; } // driver program public static void Main() { // take number input in string string s = "5468001" ; char []res = findSmallestPermutation(s); Console.WriteLine(res); } } // This code is contributed by vt_m. |
PHP
<?php // PHP program to find smallest // permutation of given number // return the smallest // number permutation function findSmallestPermutation( $s ) { $len = strlen ( $s ); $s = str_split ( $s ); // sort the string sort( $s ); // check for leading zero // in string if there are // any leading zeroes, // swap the first zero with // first non-zero number $i = 0; while ( $s [ $i ] == '0' ) $i ++; $tmp = $s [0]; $s [0] = $s [ $i ]; $s [ $i ] = $tmp ; $s =implode( "" , $s ); return $s ; } // Driver Code // take number // input in string $s = "5468001" ; $res = findSmallestPermutation( $s ); echo $res ; // This code is contributed // by mits. ?> |
Output:
1004568
Optimization :
Since character set is limited (‘0’ to ‘9’), we can write our own sort method that works in linear time (by counting frequencies of all characters)
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