Question

  map<string, pair<int, int> > common;     
 map<string, pair<int, int> >::iterator cIter = common.find(code);
        if(cIter == common.end())
        {
            pair<int, int> values(1, count);
            common.insert(make_pair(code, values));
        }
        else
            cIter->second.first++;

Anyone can help me convert the code above to Java?

 private java.util.HashMap<String, Entry<Integer, Integer>> common = new java.util.HashMap<String, Entry<Integer, Integer>>();
 Entry<Integer, Integer> cIter = common.get(code);
            if (cIter == common.) {
                Entry<Integer, Integer> values =  new AbstractMap.SimpleEntry<Integer, Integer>(1, count);
                common.put(code, values);
            } else {
                cIter.second.first++;
            }

This is what I tried does second means getValues() and first means getKey()?

Answer 1

Java doesn’t have a Pair tuple class and I’m not sure using Entry is the best choice int he case, as you need to update the “key” of the Entry.

Instead you should create a class to do this.

class Counters {
    int counter1; // use meaningful names here
    final counter2;
    public Counters(counter1, counter2) { this.counter1 = counter1; this.counter2 = counter2; }
}

Map<String, Counters> common = new HashMap<>();

Counters counters = common.get(code);
if (counters == null)
    common.put(code, counters = new Counters(1, count));
else
    counters.counter2++;

---

if (itr.second.first > max) { max = itr.second.first; minCount = itr.second.second; code = itr.next().getKey(); }

if(counters.counter1 > max) {
     max = counters.counter1;
     minCount = counters.counter2;
     code = null; // isn't needed AFAIK.
}