leastOccurrences method
Finds the least common value in the list.
Returns a record (tuple) containing the least common value and its frequency. If the list is empty, returns null.
Implementation
(bool, int)? leastOccurrences() {
if (isEmpty) {
return null;
}
final int trueCount = countTrue;
final int falseCount = length - trueCount;
// When counts are equal, false is returned (consistent behavior)
if (falseCount <= trueCount) {
return (false, falseCount);
}
return (true, trueCount);
}