FunctionTP - to test basics

FunctionalTP.java

package com.orastack;

import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.stream.Stream;
import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.Setter;

public class FunctionalTP {

  public static List<Double> runningAvg(List<Double> list) {
    int count = 0;
    List<Double> results = new ArrayList<>();
    double sum = 0;
    for (Double item : list) {
      sum += item;
      count++;
      results.add(sum / count);
    }
    return results;
  }

  public static double[] runningAvgWindow(double[] items, int windowSize) {
    double[] cumSum = new double[items.length + 1];
    int currentWindowSize = 1;
    double[] result = new double[items.length];
    for (int i = 0; i < items.length; i++) {
      cumSum[i + 1] = cumSum[i] + items[i];
      if (currentWindowSize >= windowSize) {
        result[i] = (cumSum[i + 1] - cumSum[i - windowSize + 1]) / windowSize;
      } else {
        result[i] = cumSum[i + 1] / currentWindowSize;
        currentWindowSize++;
      }
    }
    return result;
  }

  @AllArgsConstructor
  private static class Pair<T, V> {

    T first;
    V second;

  }


}