# Check if a numeric string can be split into substrings having difference between consecutive numbers equal to K

• Difficulty Level : Hard
• Last Updated : 10 Jun, 2022

Given a numeric string S consisting of N digits and a positive integer K, the task is to check if the given string can be split into more than one substrings with difference between consecutive substrings equal to K.

Examples:

Input: S = “8642”, K = 2
Output: Yes
Explanation: Split the given string as {“8”, “6”, “4”, “2”}. Now, the difference between the consecutive substrings is K(= 2).

Input: S = “1009896”, K = 0
Output: No

Approach: The given problem can be solved by generating all possible substring of the given string and check if the concatenation of any subset of the generated substring is equal to the given string S and the consecutive difference of the number as a substring is K, then print Yes. Otherwise, print No. Follow the below steps to solve the problem:

Below is the implementation of the above approach:

## C++

 `// C++ program for the above approach` `#include ``using` `namespace` `std;` `// Function to check if a numeric string``// can be split into substrings such that``// the difference between the consecutive``// substrings is K``void` `isPossible(string s, ``int` `K)``{``    ``bool` `valid = ``false``;``    ``long` `firstx = -1;` `    ``// Stores the size of the string``    ``int` `n = s.length();` `    ``// Iterate over the range [1, N] and``    ``// try each possible starting number``    ``for` `(``int` `i = 1; i <= n / 2; ++i) {` `        ``long` `x = stol(s.substr(0, i));``        ``firstx = x;` `        ``// Convert the number to string``        ``string test = to_string(x);` `        ``// Build up a sequence``        ``// starting with the number``        ``while` `(test.length() < s.length()) {``            ``x -= K;``            ``test += to_string(x);``        ``}` `        ``// Compare it with the``        ``// original string s``        ``if` `(test == s) {``            ``valid = ``true``;``            ``break``;``        ``}``    ``}` `    ``// Print the result``    ``cout << ((valid == ``true``) ? ``"Yes "` `: ``"No"``);``}` `// Driver Code``int` `main()``{``    ``string S = ``"8642"``;``    ``int` `K = 2;``    ``isPossible(S, K);` `    ``return` `0;``}`

## Python3

 `# python 3 program for the above approach` `# Function to check if a numeric string``# can be split into substrings such that``# the difference between the consecutive``# substrings is K``def` `isPossible(s,K):``    ``valid ``=` `False``    ``firstx ``=` `-``1` `    ``# Stores the size of the string``    ``n ``=` `len``(s)` `    ``# Iterate over the range [1, N] and``    ``# try each possible starting number``    ``for` `i ``in` `range``(``1``,n``/``/``2``+``1``,``1``):``        ``x ``=` `int``(s[``0``:i])``        ``firstx ``=` `x` `        ``# Convert the number to string``        ``test ``=` `str``(x)` `        ``# Build up a sequence``        ``# starting with the number``        ``while` `(``len``(test) < ``len``(s)):``            ``x ``-``=` `K``            ``test ``+``=` `str``(x)` `        ``# Compare it with the``        ``# original string s``        ``if` `(test ``=``=` `s):``            ``valid ``=` `True``            ``break` `    ``# Print the result``    ``print``(``"Yes"``) ``if` `valid ``=``=` `True` `else` `print``(``"No"``)` `# Driver Code``if` `__name__ ``=``=` `'__main__'``:``    ``S ``=` `"8642"``    ``K ``=` `2``    ``isPossible(S, K)``    ` `    ``# This code is contributed by ipg2016107.`

## Javascript

 ``

Output:

`Yes`

Time Complexity: O(N2)
Auxiliary Space: O(N)

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