Missing Number's problem.

MissingNumbers.java

public class MissingNumbers {
    public static void main(String[] args) {
        //In the below code: Array Size = 8 and n = 10.
        //So 2 missing numbers!
        int n = 10;
        int[] intArr = new int[] {3,1,2,5,4,7,10,8};
        
        MissingNumbers missingNums = new MissingNumbers();
        int[] missingNums = missingNums.findMissingNumber(intArr, n);
        
        for(int i=0;i<missingNums.length;i++) {
            System.out.println("Missing Number " + (i + 1) +  " : " + missingNums[i] + "  ");
        }
    }
    
    private int[] findMissingNumber(int[] intArray, int totalNum) {
        int numOfMissingNums = totalNum - intArray.length;
        BitSet bitSet = new BitSet(totalNum);
        
        for(int i: intArray) {
            bitSet.set(i-1);
        }
        
        int[] missingNums = new int[numOfMissingNums];
        for(int k=0;k<numOfMissingNums;k++) {
            int index = (k == 0) ? 0 : (missingNums[k - 1]);
            missingNums[k] = (bitSet.nextClearBit(index) + 1);
        }
        
        return missingNums;
    }
}