# Straight-line Number

• Last Updated : 06 May, 2021

Given a number N, the task is to check if N is an Straight-line Number or not. If N is an Straight-line Number then print “Yes” else print “No”.

A straight-line Number is a number greater than 99 in which the digits form an Arithmetic Progression

Examples:

Input: N = 135
Output: Yes
Explanation:
The digits of the number N are 1, 3, and 5.
1 3 5 is an AP with d = 2

Input: N = 136
Output: No

Approach: The idea is to convert the given number N into a string and check, if differences between consecutive digits are same or not. If the difference between all the corresponding digit are same then print “Yes” else print “No”.

Below is the implementation of the above approach:

## C++

 `// C++ program for the above approach``#include ``using` `namespace` `std;` `// Function to check if N is a``// Straight Line number or not``bool` `isStraighLineNum(``int` `N)``{``    ``// N must be > 99``    ``if` `(N <= 99)``        ``return` `false``;` `    ``string str = to_string(N);` `    ``// Difference between consecutive``    ``// digits must be same``    ``int` `d = str[1] - str[0];` `    ``for` `(``int` `i = 2; i < str.length(); i++)``        ``if` `(str[i] - str[i - 1] != d)``            ``return` `false``;` `    ``return` `true``;``}` `// Driver Code``int` `main()``{``    ``// Given Number N``    ``int` `N = 135;` `    ``// Function Call``    ``if` `(isStraighLineNum(n))``        ``cout << ``"Yes"``;``    ``else``        ``cout << ``"No"``;``}`

## Java

 `// Java program for the above approach``class` `GFG{` `// Function to check if N is a``// Straight Line number or not``static` `boolean` `isStraighLineNum(``int` `N)``{``    ` `    ``// N must be > 99``    ``if` `(N <= ``99``)``        ``return` `false``;` `    ``String s = Integer.toString(N);` `    ``// Difference between consecutive``    ``// digits must be same``    ``int` `d = s.charAt(``1``) - s.charAt(``0``);` `    ``for``(``int` `i = ``2``; i < s.length(); i++)``       ``if` `(s.charAt(i) - s.charAt(i - ``1``) != d)``           ``return` `false``;` `    ``return` `true``;``}` `// Driver code``public` `static` `void` `main(String[] args)``{``    ` `    ``// Given Number N``    ``int` `n = ``135``;` `    ``// Function Call``    ``if` `(isStraighLineNum(n))``    ``{``        ``System.out.println(``"Yes"``);``    ``}``    ``else``    ``{``        ``System.out.println(``"No"``);``    ``}``}``}` `// This code is contributed by Pratima Pandey`

## Python3

 `# Python3 program for the above approach` `# Function to check if N is a``# Straight Line number or not``def` `isStraighLineNum(N):` `    ``# N must be > 99``    ``if` `(N <``=` `99``):``        ``return` `False``;` `    ``str1 ``=` `str``(N);` `    ``# Difference between consecutive``    ``# digits must be same``    ``d ``=` `int``(str1[``1``]) ``-` `int``(str1[``0``]);` `    ``for` `i ``in` `range``(``2``, ``len``(str1)):``        ``if` `(``int``(str1[i]) ``-``            ``int``(str1[i ``-` `1``]) !``=` `d):``            ``return` `False``;` `    ``return` `True``;` `# Driver Code` `# Given Number N``N ``=` `135``;` `# Function Call``if` `(isStraighLineNum(N)):``    ``print``(``"Yes"``);``else``:``    ``print``(``"No"``);` `# This code is contributed by Code_Mech`

## C#

 `// C# program for the above approach``using` `System;``class` `GFG{` `// Function to check if N is a``// Straight Line number or not``static` `bool` `isStraighLineNum(``int` `N)``{``    ` `    ``// N must be > 99``    ``if` `(N <= 99)``        ``return` `false``;` `    ``string` `s = N.ToString();` `    ``// Difference between consecutive``    ``// digits must be same``    ``int` `d = s[1] - s[0];` `    ``for``(``int` `i = 2; i < s.Length; i++)``       ``if` `(s[i] - s[i - 1] != d)``           ``return` `false``;` `    ``return` `true``;``}` `// Driver code``public` `static` `void` `Main()``{``    ` `    ``// Given Number N``    ``int` `n = 135;` `    ``// Function Call``    ``if` `(isStraighLineNum(n))``    ``{``        ``Console.Write(``"Yes"``);``    ``}``    ``else``    ``{``        ``Console.Write(``"No"``);``    ``}``}``}` `// This code is contributed by Code_Mech`

## Javascript

 ``

Output:

`Yes`

Time Complexity: O(log10N)

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