Optimized accept-reject sequence to approach target frame. (Pokemon Sun / Moon)

JumpFrame.java

import java.util.ArrayList;
import java.util.Scanner;

/**
 * This code generate optimized accept-reject sequence to approach target frame.
 * Background: Pokemon Sun / Moon Random Number
 */
public class JumpFrame {
  enum Op {Accept, Reject};

  static class Frame {
    int prev;
    Op op;
    int distance;

    Frame(int prev, Op op, int distance) {
      this.prev = prev;
      this.op = op;  // Operation on `prev' frame.
      this.distance = distance;
    }
  }

  Frame[] frames;

  private void updateNextFrame(int next, int curr, Op op) {
    if (next < frames.length && frames[curr].distance + 1 < frames[next].distance) {
      frames[next].distance = frames[curr].distance + 1;
      frames[next].prev = curr;
      frames[next].op = op;
    }
  }

  public void dp(int[] next) {
    frames = new Frame[next.length];
    for (int i = 0; i < next.length; i++) {
      frames[i] = new Frame(i - 1, Op.Reject, i);
    }

    for (int i = 0; i < next.length; i++) {
      updateNextFrame(i + next[i], i, Op.Accept);
      updateNextFrame(i + 1, i, Op.Reject);
    }
  }

  public void route(int target) {
    if (target > 0) {
      route(frames[target].prev);
      System.out.println("frame " + frames[target].prev + ": " + frames[target].op);
    }
  }

  public static void main(String[] args) {
    Scanner input = new Scanner(System.in);

    System.out.print("Input target frame: ");
    int target = input.nextInt();

    System.out.println("Input frame sequence: <frame.no> <consume>, end with EOF.");
    ArrayList<Integer> array = new ArrayList<>();
    while (input.hasNext()) {
      input.nextInt();
      array.add(input.nextInt());
    }

    JumpFrame jf = new JumpFrame();
    jf.dp(array.stream().mapToInt(e -> e).toArray());
    jf.route(target);
  }
}