Two comma separated strings exist.
The first string is essentially the keys and the second is the linked values,
The first string needs to be in ascending order while retaining any duplicate values, and the second string needs to follow in suit to maintain the sequence as such.
Looked at hashmaps and tuples without success so far. System is Java 6
String A = "3, 4, 1, 2, 3"
String B = "19, 24, 32, 68, 50"
Result Output needed
String A = "1, 2, 3, 3, 4"
String B = "32, 68, 19, 50, 24"
You have a multitude of possibilities to realize your requirements. Here are two examples (existing in parallel within the example code):
Map<Integer, List<Integer>>
that holds a key and all values it has in a List
See this example and pay attention to the code comments:
public class StackoverflowMain {
public static void main(String[] args) {
String a = "3, 4, 1, 2, 3";
String b = "19, 24, 32, 68, 50";
// Map-approach: use a map that maps a key to a list of values
Map<Integer, List<Integer>> ab = new TreeMap<>();
// Pair-approach: make a sortable POJO that holds a key and a value only
// and create a data structure that holds them sorted
SortedSet<Pair> pairList = new TreeSet<Pair>();
// split both Strings by comma
String[] aSplit = a.split(",");
String[] bSplit = b.split(",");
// check if the length of the resulting arrays is the same
if (aSplit.length == bSplit.length) {
// if yes, go through the arrays of numbers
for (int i = 0; i < aSplit.length; i++) {
int key = Integer.parseInt(aSplit[i].trim());
int value = Integer.parseInt(bSplit[i].trim());
// in the Pair-approach, you just have to create a Pair with the value found
Pair pair = new Pair(key, value);
// and add it to the set of pairs
pairList.add(pair);
// the following check is only needed for the Map-solution
if (ab.containsKey(key)) {
// if the key is already present,
// just add the new value to its value list
ab.get(key).add(value);
// sort the value list each time a new value has been added
ab.get(key).sort(Comparator.naturalOrder());
} else {
// if the key is not present in the Map so far,
// create a new List for the value
List<Integer> valueList = new ArrayList<>();
// add the value to that list
valueList.add(value);
// and put both into the Map
ab.put(key, valueList);
}
}
} else {
System.err.println("The Strings have different amounts of elements!");
}
// print what's in the Map
System.out.println("Map-approach:");
for (int key : ab.keySet()) {
List<Integer> value = ab.get(key);
for (int val : value) {
System.out.println(key + " : " + val);
}
}
System.out.println("————————————————");
System.out.println("Pairs-approach:");
for (Pair pair : pairList) {
System.out.println(pair.key + " : " + pair.val);
}
}
/**
* This class is needed for the Pair-approach.
* It is comparable (and by that, sortable) and will be sorted by key
* and if the keys are equal, it will sort by value.
*/
static class Pair implements Comparable<Pair> {
int key;
int val;
Pair(int key, int value) {
this.key = key;
this.val = value;
}
@Override
public int compareTo(Pair otherPair) {
if (key == otherPair.key) {
if (val == otherPair.val) {
return 0;
} else if (val < otherPair.key) {
return -1;
} else {
return 1;
}
} else if (key < otherPair.key) {
return -1;
} else {
return 1;
}
}
}
}
This code produces the following output:
Map-approach:
1 : [32]
2 : [68]
3 : [19, 50]
4 : [24]
————————————————
Pairs-approach:
1 : 32
2 : 68
3 : 19
3 : 50
4 : 24
EDIT
Since the Pair
-approach does not sort correctly, I came up with this Map
-approach:
public class StackoverflowMain {
public static void main(String[] args) {
String a = "3, 4, 1, 3, 3, 2, 3";
String b = "5, 24, 35, 99, 32, 68, 19";
// Map-approach: use a map that maps a key to a list of values
Map<Integer, List<Integer>> ab = new TreeMap<>();
// split both Strings by comma
String[] aSplit = a.split(",");
String[] bSplit = b.split(",");
// check if the length of the resulting arrays is the same
if (aSplit.length == bSplit.length) {
// if yes, go through the arrays of numbers
for (int i = 0; i < aSplit.length; i++) {
int key = Integer.parseInt(aSplit[i].trim());
int value = Integer.parseInt(bSplit[i].trim());
// the following check is only needed for the Map-solution
if (ab.containsKey(key)) {
// if the key is already present, just add the new value to its value list
ab.get(key).add(value);
// sort the value list each time a new value has been added
ab.get(key).sort(Comparator.naturalOrder());
} else {
// if the key is not present in the Map so far, create a new List for the value
List<Integer> valueList = new ArrayList<>();
// add the value to that list
valueList.add(value);
// and put both into the Map
ab.put(key, valueList);
}
}
} else {
System.err.println("The Strings have different amounts of elements!");
}
// print what's in the Map
System.out.println("Map-approach:");
for (int key : ab.keySet()) {
List<Integer> value = ab.get(key);
for (int val : value) {
System.out.println(key + " : " + val);
}
}
}
}
It is shorter and uses a Map<Integer, List<Integer>>
and sorts the List<Integer>
every time a new value gets added (apart from the first value, which doesn't need a sort). That needed another loop in the output code, but you don't have to create a new class.
It produces the following output:
Map-approach:
1 : 35
2 : 68
3 : 5
3 : 19
3 : 32
3 : 99
4 : 24