countPairsWithDiff function

int countPairsWithDiff(
  1. List<int> nums,
  2. int diff
)

Counting Pairs with Specific Difference.

Implementation

int countPairsWithDiff(List<int> nums, int diff) {
  final set = nums.toSet();
  var count = 0;
  for (final num in set) {
    if (set.contains(num + diff)) count++;
  }
  return count;
}