715. Range Module

A Range Module is a module that tracks ranges of numbers. Your task is to design and implement the following interfaces in an efficient manner.

addRange(int left, int right) Adds the half-open interval [left, right), tracking every real number in that interval. Adding an interval that partially overlaps with currently tracked numbers should add any numbers in the interval [left, right) that are not already tracked.

queryRange(int left, int right) Returns true if and only if every real number in the interval [left, right) is currently being tracked.

removeRange(int left, int right) Stops tracking every real number currently being tracked in the interval [left, right).

Example 1:

addRange(10, 20): null
removeRange(14, 16): null
queryRange(10, 14): true (Every number in [10, 14) is being tracked)
queryRange(13, 15): false (Numbers like 14, 14.03, 14.17 in [13, 15) are not being tracked)
queryRange(16, 17): true (The number 16 in [16, 17) is still being tracked, despite the      

class RangeModule {
    TreeSet<Interval> ranges;
    public RangeModule() {
        ranges = new TreeSet();
    }

    public void addRange(int left, int right) {
        Iterator<Interval> itr = ranges.tailSet(new Interval(0, left - 1)).iterator();
        while (itr.hasNext()) {
            Interval iv = itr.next();
            if (right < iv.left) break;
            left = Math.min(left, iv.left);
            right = Math.max(right, iv.right);
            itr.remove();
        }
        ranges.add(new Interval(left, right));
    }

    public boolean queryRange(int left, int right) {
        Interval iv = ranges.higher(new Interval(0, left));
        return (iv != null && iv.left <= left && right <= iv.right);
    }

    public void removeRange(int left, int right) {
        Iterator<Interval> itr = ranges.tailSet(new Interval(0, left)).iterator();
        ArrayList<Interval> todo = new ArrayList();
        while (itr.hasNext()) {
            Interval iv = itr.next();
            if (right < iv.left) break;
            if (iv.left < left) todo.add(new Interval(iv.left, left));
            if (right < iv.right) todo.add(new Interval(right, iv.right));
            itr.remove();
        }
        for (Interval iv: todo) ranges.add(iv);
    }
}

class Interval implements Comparable<Interval>{
    int left;
    int right;

    public Interval(int left, int right){
        this.left = left;
        this.right = right;
    }

    public int compareTo(Interval that){
        if (this.right == that.right) return this.left - that.left;
        return this.right - that.right;
    }
}

/**
 * Your RangeModule object will be instantiated and called as such:
 * RangeModule obj = new RangeModule();
 * obj.addRange(left,right);
 * boolean param_2 = obj.queryRange(left,right);
 * obj.removeRange(left,right);
 */