I am trying to get the key with maximum number of values (not max value). I ave tried a couple of thing like counting values iterating over each key. But they boil down to problem finding a key from value which is problematic when we have same values.
// calculate the length
for(String key : map.keySet())
{
len.add(map.get(key).size());
}
// sort the length
Collections.sort(len, Collections.reverseOrder() );
If you're using Java 8, this could just be
String maxKey = map.entrySet().stream()
.max(Comparator.comparingInt(entry -> entry.getValue().size()))
.get().getKey();
if not, I'd tend to write this as
String maxKey = Collections.max(map.entrySet(),
new Comparator<Map.Entry<String, List<Value>>>() {
@Override public int compare(
Map.Entry<String, List<Value>> e1, Map.Entry<String, List<Value>> e2) {
return Integer.compare(e1.getValue().size(), e2.getValue().size());
}
}).getKey();
...or, you could just write
String maxKey = null;
int maxCount = 0;
for (Map.Entry<String, List<Value>> entry : map.entrySet()) {
if (entry.getValue().size() > maxCount) {
maxKey = entry.getKey();
maxCount = entry.getValue().size();
}
}
return maxKey;
String maxKey = null;
for (String key : map.keySet())
{
if (maxKey == null || map.get(key).size() > map.get(maxKey).size())
{
maxKey = key;
}
}
This would be my solution to the problem. After execution, maxKey
is key with the most values.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.