SatouMizuMaze

import java.util.ArrayList;
import java.util.List;

public class SatouMizuMaze {
  public static void main(String[] args) {
    List<SatouMizu> a = new ArrayList<>();
    for (int i = 10; i < 51; ++i) {
      a.add(new SatouMizu(110 - i, 20, i));
    }
    System.out.println(a.stream().reduce((x, y) -> x.mazeru(y)).get());
  }
}

class Mizu {
  protected double mizu_shitsuryou, ondo;

  public Mizu(double s, double o) {
    mizu_shitsuryou = s;
    ondo = o;
  }

  public Mizu mazeru(Mizu aite) {
    return new Mizu(
        mizu_shitsuryou + aite.mizu_shitsuryou,
        (ondo * mizu_shitsuryou + aite.ondo * aite.mizu_shitsuryou)
            / (mizu_shitsuryou + aite.mizu_shitsuryou));
  }

  public String toString() {
    return String.format("mizu: mizu_shitsuryou = %.1f, ondo = %.1f", mizu_shitsuryou, ondo);
  }
}

class SatouMizu extends Mizu {
  protected double satou_shitsuryou;

  public SatouMizu(double s, double o, double st) {
    super(s, o);
    satou_shitsuryou = st;
  }

  public SatouMizu mazeru(SatouMizu aite) {
    return new SatouMizu(
        mizu_shitsuryou + aite.mizu_shitsuryou,
        (ondo * mizu_shitsuryou + aite.ondo * aite.mizu_shitsuryou)
            / (mizu_shitsuryou + aite.mizu_shitsuryou),
        satou_shitsuryou + aite.satou_shitsuryou);
  }

  public String toString() {
    return String.format(
        "satoumizu: mizu_shitsuryou = %.1f, ondo = %.1f, satou_shitsuryou = %.1f, noudo = %.1f%%",
        mizu_shitsuryou,
        ondo,
        satou_shitsuryou,
        100.0 * satou_shitsuryou / (satou_shitsuryou + mizu_shitsuryou));
  }
}