Run results for: Array duplicate removal for duplicates exceeding `N`-number

Test name	Executions per second
original duplicate removal	39272.0 Ops/sec
2-pass approach	41699.6 Ops/sec
2-pass with filtering	48679.2 Ops/sec
2pf-obj	43858.6 Ops/sec

original duplicate removal

// Remove duplicates that occur 3 or more times in an array
// keeping unique values and those with less than 3
function removeMany(arr) {
  const newArr = Array.from(arr).sort()
  let count = 0;
  let result = []

  newArr.forEach((value, index, ar) => {
    count += 1;
    // refactored afterwards from (ar[index + 1] !== value)
    if (ar.lastIndexOf(value) <= index && count <= 2) {
      for (var i = 0; i < arr.length; i++) {
        if (arr[i] === value) {
          result.push(arr[i])
        }
      }
      count = 0
    } else if (ar[index + 1] !== value) {
      count = 0;
    }
  });

  // +1 is there anyway to return a result that mimicks the original order of `numbers`?
  return result;  // [1, 2, 2, 3, 4, 4]
}
const numbers = [1, 2, 3, 2, 4, 4, 5, 5, 5, 5];
console.log(removeMany(numbers));

2-pass approach

 // Remove duplicates that occur 3 or more times in an array
    // keeping unique values and those with less than 3
    function removeMany(arr) {
      let countMappings = arr.reduce(function(carry, item) {
          if (carry[item]!== undefined) {
            carry[item]++;
          }
          else {
            carry[item] = 1;
          }
          return carry;
      }, {});
      return arr.reduce(function(final, item) {
        if (countMappings[item] <3) {
          final.push(item);
        }
        return final;
      }, []);
    }
    const numbers = [1, 2, 3, 2, 4, 4, 5, 5, 5, 5];
    console.log(removeMany(numbers));

2-pass with filtering

function removeMany(numbers, max) {
    const numberMap = numbers.reduce((map, num) => {
        map[num] = map[num] ? map[num] + 1 : 1;
        return map;
    }, []);
    
    return numbers.filter(num => numberMap[num] < max);
}

const numbers = [1, 2, 3, 2, 4, 4, 5, 5, 5, 5];
console.log(removeMany(numbers, 3));

2pf-obj

function removeMany(numbers, max) {
    const numberMap = numbers.reduce((map, num) => {
        if (!map[num]) map[num] = 0;
        map[num]++;
        return map;
    }, {});
    
    return numbers.filter(num => numberMap[num] < max);
}

const numbers = [1, 2, 3, 2, 4, 4, 5, 5, 5, 5];
console.log(removeMany(numbers, 3));

Run results for: Array duplicate removal for duplicates exceeding `N`-number

https://codereview.stackexchange.com/q/175067/120114

original duplicate removal

2-pass approach

2-pass with filtering

2pf-obj