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Find the closest and smaller tidy number
• Difficulty Level : Easy
• Last Updated : 07 May, 2021

Tidy Number are those number whose digits are arranged in non-decreasing order. Here, we are given a number and we have to find another number that is smaller but closest to the given number and also that number should be tidy, i.e., their digit should be in non-decreasing order.

Examples:

```Input  : 91234
Output : 89999
Tidy property is violated by appearing 1 after 9.
So, we will reduce 9 by 1 and the number right
to it will be replaced by 9. So, generated tidy
number is 89999.

Input  : 45000
Output : 44999```

The idea is to traverse from end. Whenever tidy property is violated, we reduce digit by one and make all subsequent digits 9.

## C++

 `// C++ program to find closest``// tidy number smaller than the``// given number``#include``using` `namespace` `std;` `char``* tidyNum(``char` `str[], ``int` `len)``{``    ``for` `(``int` `i = len-2; i >= 0; i--)``    ``{``        ``// check whether string violates tidy property``        ``if` `(str[i] > str[i+1])``        ``{``            ``// if string violates tidy property, then``            ``// decrease the value stored at that index by 1``            ``// and replace all the value stored right to``            ``// that index by 9``            ``(``char``)str[i]--;``            ``for` `(``int` `j=i+1; j

## Java

 `// Java program to find closest``// tidy number smaller than the``// given number``import` `java.io.*;``class` `GFG``{``static` `String tidyNum(String str1,``                      ``int` `len)``{``    ``char``[] str = str1.toCharArray();``    ``for` `(``int` `i = len - ``2``; i >= ``0``; i--)``    ``{``        ``// check whether string``        ``// violates tidy property``        ``if` `(str[i] > str[i + ``1``])``        ``{``            ``// if string violates tidy``            ``// property, then decrease the``            ``// value stored at that index``            ``// by 1 and replace all the value``            ``// stored right to that index by 9``            ``str[i]--;``            ``for` `(``int` `j = i + ``1``; j < len; j++)``                ``str[j] = ``'9'``;``        ``}``    ``}``    ``return` `String.valueOf(str);``}` `// Driver code``public` `static` `void` `main(String[] args)``{``    ``String str = ``"11333445538"``;``    ``int` `len = str.length();``    ` `    ``// num will store closest tidy number``    ``System.out.println(tidyNum(str, len));``}``}` `// This code is contributed by mits`

## Python3

 `# Python 3 program to find closest``# tidy number smaller than the``# given number` `def` `tidyNum(``str``, ``len``):` `    ``for` `i ``in` `range``(``len``-``2``, ``-``1``, ``-``1``):``    ` `        ``# check whether string``        ``# violates tidy property``        ``if` `(``str``[i] > ``str``[i``+``1``]):``        ` `            ``# if string violates tidy``            ``# property, then decrease the``            ``# value stored at that index by 1``            ``# and replace all the value``            ``# stored right to that index by 9``            ``str``[i] ``-``=` `1``            ``for` `j ``in` `range``(i``+``1``, ``len``):``                ``str``[j] ``=` `9``        ` `    ``return` `str` `# Driver code``str` `=` `[``1``,``1``,``3``,``3``,``3``,``4``,``4``,``5``,``5``,``3``,``8``]``len` `=` `len``(``str``)``    ` `# num will store closest tidy number``num ``=` `tidyNum(``str``, ``len``)` `for` `i ``in` `range``(``0``,``len``):``    ``print``(``str``[i], end ``=` `"")` `# This code is contributed by``# Smitha Dinesh Semwal`

## C#

 `// C# program to find closest``// tidy number smaller than the``// given number``using` `System;` `class` `GFG``{``static` `String tidyNum(String str1, ``int` `len)``{``    ``char``[] str = str1.ToCharArray();``    ``for` `(``int` `i = len - 2; i >= 0; i--)``    ``{``        ``// check whether string``        ``// violates tidy property``        ``if` `(str[i] > str[i + 1])``        ``{``            ``// if string violates tidy``            ``// property, then decrease the``            ``// value stored at that index``            ``// by 1 and replace all the value``            ``// stored right to that index by 9``            ``str[i]--;``            ``for` `(``int` `j = i + 1; j < len; j++)``                ``str[j] = ``'9'``;``        ``}``    ``}``    ``string` `s = ``new` `string``(str);``    ``return` `s;``}` `// Driver code``static` `void` `Main()``{``    ``String str = ``"11333445538"``;``    ``int` `len = str.Length;``    ` `    ``// num will store closest tidy number``    ``Console.WriteLine(tidyNum(str, len));``}``}` `// This code is contributed by mits`

## PHP

 `= 0; ``\$i``--)``    ``{``        ``// check whether string``        ``// violates tidy property``        ``if` `(``\$str``[``\$i``] > ``\$str``[``\$i` `+ 1])``        ``{``            ``// if string violates tidy``            ``// property, then decrease``            ``// the value stored at that``            ``// index by 1 and replace all``            ``// the value stored right to``            ``// that index by 9``            ``\$x` `= ord(``\$str``[``\$i``]);``            ``\$x``--;``            ``\$str``[``\$i``] = ``chr``(``\$x``);``            ``for` `(``\$j` `= ``\$i` `+ 1; ``\$j` `< ``\$len``; ``\$j``++)``                ``\$str``[``\$j``] = ``'9'``;``        ``}``    ``}``    ``return` `\$str``;``}` `// Driver code``\$str` `= ``"11333445538"``;``\$len` `= ``strlen``(``\$str``);` `// num will store``// closest tidy number``\$num` `= tidyNum(``\$str``, ``\$len``);``echo` `\$num``;` `// This code is contributed by mits``?>`

## Javascript

 ``

Output:

`11333444999`

References :
This question is asked in Google Code Jam 2017 qualification round.

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