largest sum of contiguous subarray No Larger than k

I was influenced by the classic solution mentioned in the question. This problem can be simply solved by an o(n^2) solution:

private int maxSumSubArray(int[] a , int k){

    int max = Integer.MIN_VALUE;
    for(int i=0;i<a.length;i++){
        int tsum = 0;
        for(int j=i;j<a.length;j++){
            tsum += a[j];
            if(tsum <= k) max=Math.max(max,tsum);
        }
    }

    return max;
}

This is an o(nlogn) solution referred to https://www.quora.com/Given-an-array-of-integers-A-and-an-integer-k-find-a-subarray-that-contains-the-largest-sum-subject-to-a-constraint-that-the-sum-is-less-than-k

private int maxSumSubArray(int[] a , int k){

    int max = Integer.MIN_VALUE;
    int sumj = 0;
    TreeSet<Integer> ts = new TreeSet();
    ts.add(0);

    for(int i=0;i<a.length;i++){
        sumj += a[i];
        if (sumj == k) return k;
        Integer gap = ts.ceiling(sumj - k);
        if(gap != null) max = Math.max(max, sumj - gap);
        ts.add(sumj);
    }
    return max;
}