Interview20

Question 1 :

Below gives the expected results for the used sample -

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
public class Techlandia {
static HashMap<String, List<String>> temp = new HashMap<>();
static ArrayList<String> values = new ArrayList<>();
static ArrayList<String> news = new ArrayList<>();
static HashMap<String, String> olds = new HashMap<>();
static List<String> results = new ArrayList<>();

public static void main(String[] args) {
  List<String> boxList = new ArrayList<>();
  boxList.add("ykc 82 01");
  boxList.add("eo first qpx");
  boxList.add("09z cat hamster");
  boxList.add("06f 12 25 6");
  boxList.add("az0 first qpx");
  boxList.add("236 cat dog rabbit snake");
  orderedJunctionBoxes(6, boxList).forEach(System.out::println);
}

public static List<String> orderedJunctionBoxes(int numberOfBoxes,
   List<String> boxList) {
  boxList.forEach(a -> {
   int p = a.indexOf(" ");
   String version = a.substring(p+1);
   String id = a.substring(0, p);
   String[] vSplit = version.split(" ");
   try {
    Integer.parseInt(vSplit[0]);
    news.add(a);
   } catch(NumberFormatException nfe) {
    List<String> ls;
    if((ls=temp.get(version)) == null) {
     ls = new ArrayList<>();
     ls.add(id);
     temp.put(version, ls);
    } else {
     ls.add(id);
     temp.put(version, ls);
    }

    olds.put(id, a);
    values.add(version);
   }
  });
  Collections.sort(values);

  values.forEach(a -> {
   List<String> vals = temp.get(a);
   Collections.sort(vals);
   vals.forEach(x -> {
    results.add(olds.get(x));
   });
   temp.put(a, new ArrayList<String>());
  });

  news.forEach(a -> results.add(a));

  return results;
}
}

Question 2 :

Below gives the expected results for the used sample -

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;

public class Apps {

public static void main(String[] args) {
  List<List<Integer>> foregroundAppList = new ArrayList<>();
  List<Integer> temp = new ArrayList<>();
  temp.add(1);
  temp.add(3);
  foregroundAppList.add(temp);
  temp = new ArrayList<>();
  temp.add(2);
  temp.add(5);
  foregroundAppList.add(temp);
  temp = new ArrayList<>();
  temp.add(3);
  temp.add(7);
  foregroundAppList.add(temp);
  temp = new ArrayList<>();
  temp.add(4);
  temp.add(10);
  foregroundAppList.add(temp);
  List<List<Integer>> backgroundAppList = new ArrayList<>();
  temp = new ArrayList<>();
  temp.add(1);
  temp.add(2);
  backgroundAppList.add(temp);
  temp = new ArrayList<>();
  temp.add(2);
  temp.add(3);
  backgroundAppList.add(temp);
  temp = new ArrayList<>();
  temp.add(3);
  temp.add(4);
  backgroundAppList.add(temp);
  temp = new ArrayList<>();
  temp.add(4);
  temp.add(5);
  backgroundAppList.add(temp);
   optimalUtilization(7, foregroundAppList, backgroundAppList).forEach(System.out::println);
}

static List<List<Integer>> optimalUtilization(int deviceCapacity,
   List<List<Integer>> foregroundAppList,
   List<List<Integer>> backgroundAppList) {
  List<Integer> foregroundCap = new ArrayList<>();
  List<Integer> backgroundCap = new ArrayList<>();
  HashMap<Integer, Integer> foreCaps = new HashMap<>();
  HashMap<Integer, Integer> backCaps = new HashMap<>();
  int tempV;
  int max = 0;
  foregroundAppList.forEach(a -> {
   foregroundCap.add(a.get(1));
   foreCaps.put(a.get(1), a.get(0));
  });
  backgroundAppList.forEach(a ->{
   backgroundCap.add(a.get(1));
   backCaps.put(a.get(1), a.get(0));
  });
  Collections.sort(backgroundCap);
  int bl = backgroundCap.size();
  Collections.sort(foregroundCap);
  int fl = foregroundCap.size();
  int k = fl < bl ? fl : bl;
  List<List<Integer>> results = new ArrayList<>(k);
  for(int x = fl-1; x >= 0; x--) {
   int a = foregroundCap.get(x);
   int rem = deviceCapacity - a;
   if(rem <= 0)
    continue;
   if(backCaps.containsKey(rem)) {
    List<Integer> temp = new ArrayList<>();
    temp.add(foreCaps.get(a));
    temp.add(backCaps.get(rem));
    if(results.isEmpty())
     results.add(temp);
    else
     results.add(results.size()-1,temp);
   } else {
    for(int i = bl-1; i >= 0 && results.isEmpty(); i--) {
     if(rem-backgroundCap.get(i) > max) {
      tempV = backgroundCap.get(i);
      List<Integer> temp = new ArrayList<>();
      temp.add(foreCaps.get(a));
      temp.add(backCaps.get(tempV));
      results.add(temp);
      max = a + tempV;
      break;
     }
    }
   }
  }
  return results;
}
}