# Java Program for Largest K digit number divisible by X

Integers X and K are given. The task is to find highest K-digit number divisible by X.

Examples:

```Input : X = 30, K = 3
Output : 990
990 is the largest three digit
number divisible by 30.

Input : X = 7, K = 2
Output : 98
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

An efficient solution is to use below formula.

```ans = MAX - (MAX % X)
where MAX is the largest K digit
number which is  999...K-times```

The formula works on simple school method division. We remove remainder to get the largest divisible number.

 `// Java code to find highest ` `// K-digit number divisible by X ` ` `  `import` `java.io.*; ` `import` `java.lang.*; ` ` `  `class` `GFG { ` `    ``public` `static` `double` `answer(``double` `X, ``double` `K) ` `    ``{ ` `        ``double` `i = ``10``; ` `        ``// Computing MAX ` `        ``double` `MAX = Math.pow(i, K) - ``1``; ` ` `  `        ``// returning ans ` `        ``return` `(MAX - (MAX % X)); ` `    ``} ` ` `  `    ``public` `static` `void` `main(String[] args) ` `    ``{ ` ` `  `        ``// Number whose divisible is to be found ` `        ``double` `X = ``30``; ` ` `  `        ``// Max K-digit divisible is to be found ` `        ``double` `K = ``3``; ` ` `  `        ``System.out.println((``int``)answer(X, K)); ` `    ``} ` `} ` ` `  `// Code contributes by Mohit Gupta_OMG <(0_o)> `

Output:

```990
```

To understand Math.pow() function, please refer point 18 of the article :
https://www.geeksforgeeks.org/java-lang-math-class-java-set-2/

Please refer complete article on Largest K digit number divisible by X for more details!

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