found solution here https://www.tutorialspoint.com/program-to-find-number-of-sequences-after-adjacent-k-swaps-and-at-most-k-swaps-in-python but can't understand the idea behind the solution

any idea how to use inversion here?

This can be solved really simple without any model and training data. defective Takata airbags

Here is my solution in java, javascript, python, C, C++, Csharp HackerRank Swap Permutation Problem Solution

!/bin/python3

import os import sys

#

Complete the swapPermutation function below.

# def swapPermutation(n, k): # # Write your code here. # mod = 1000000007 s = [1] + [0] * k t = [1] + [0] * k for i in range(1, n): temp = sum(s[max(k - i, 0):k]) % mod for j in range(k, 0, -1): s[j] = (s[j] + temp) % mod if j > i: temp = (temp + s[j - i - 1] - s[j - 1]) % mod else: temp = (temp - s[j - 1]) % mod for j in range(k, 0, -1): t[j] = (t[j] + i * t[j - 1]) % mod return sum(s[k % 2::2]) % mod, sum(t) % mod

if name == 'main': fptr = open(os.environ['OUTPUT_PATH'], 'w')

nk = input().split()

n = int(nk[0])

k = int(nk[1])

result = swapPermutation(n, k)

fptr.write(' '.join(map(str, result)))
fptr.write('\n')

• fptr.close(