My whole code on java

import java.util.Scanner;

/** * Dortmund Dilemma: * https://www.hackerrank.com/challenges/dortmund-dilemma * * Based on editorial (which has 2 typos: k^n instead of n^k and * sum of P[n][j] instead of G[n][j]): * https://hr-filepicker.s3.amazonaws.com/101jun14/3124-Dortmund-Dilemma.pdf * * My original solution was too slow because it did not use caching. At the end I * rewrote my code by reading another user's code: * https://github.com/linjiyuan90/OJ_Code/blob/master/hackerrank/DortmundDilemma.cc */ public class DortmundDilemma { public static final int MAX_N = 100000; public static final int MAX_K = 26; public static final long MOD = 1000000009;

/** binomial coefficient / static long[][] C; /* * Total number of all possible strings that contain NO prefix-suffix * matches and NOT NECESSARILY all K letters (strings may be made with * fewer unique letters) for every N, K combinations. / static long[][] F; /* * Total number of all possible strings that contain at least one * prefix-suffix match by subtracting from k^N (all possible K letter combinations * of length N) all possible strings that contain NO prefix-suffix matches * (strings may include NOT all K letters). */ static long[][] G; static long[][] P;

public static void main(String[] args) { C = new long[MAX_K+1][MAX_K+1]; for (int i = 0; i <= MAX_K; i++) { C[i][0] = C[i][i] = 1; for (int j = 1; j < i; j++) { C[i][j] = (C[i-1][j] + C[i-1][j-1]) % MOD; } }

F = new long[MAX_N+1][MAX_K+1];
G = new long[MAX_N+1][MAX_K+1];
P = new long[MAX_N+1][MAX_K+1];
for (int k = 1; k <= MAX_K; k++) {
  F[1][k] = k;
  long kn = k;

  for (int n = 2; n <= MAX_N; n++) {
    kn = kn * k % MOD;
    if (n % 2 == 1) {
      F[n][k] = F[n-1][k] * k % MOD;
    } else {
      F[n][k] = (F[n-1][k] * k % MOD - F[n/2][k] + MOD) % MOD;
    }
    G[n][k] = (kn - F[n][k] + MOD) % MOD;
    P[n][k] = G[n][k];
    for (int j = 1; j < k; j++) {
      P[n][k] = (P[n][k] - P[n][j] * C[k][j] % MOD + MOD) % MOD;
    }
  }
}

Scanner scanner = new Scanner(System.in);
for (int t = scanner.nextInt(); t > 0; t--) {
  int N = scanner.nextInt(), K = scanner.nextInt();
  System.out.println(P[N][K] * C[26][K] % MOD);
}
scanner.close();

} }