# Range Module

This page explains Java solution to problem `Range Module` using `TreeMap` data structure.

## Problem Statement

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:

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 remove operation)

## Solution

If you have any suggestions in below code, please create a pull request by clicking here.
``````
package com.vc.hard;

import java.util.*;

class RangeModule {

private TreeMap<Integer, Integer> rangeMap;

public RangeModule() {
rangeMap = new TreeMap<Integer, Integer>();
}

public void addRange(int left, int right) {
Integer pre = rangeMap.floorKey(left);
Integer next = rangeMap.floorKey(right);

if(pre != null && rangeMap.get(pre) >= left) {
left = pre;
}

if(next != null && rangeMap.get(next) > right) {
right = rangeMap.get(next);
}

rangeMap.subMap(left, true, right, true).clear();
rangeMap.put(left, right);
}

public boolean queryRange(int left, int right) {
Integer pre = rangeMap.floorKey(left);
if(pre != null && rangeMap.get(pre) >= right) return true;
else return false;
}

public void removeRange(int left, int right) {
Integer pre = rangeMap.floorKey(left);
Integer next = rangeMap.floorKey(right);

if(next != null && rangeMap.get(next) > right) {
rangeMap.put(right, rangeMap.get(next));
}

if(pre != null && rangeMap.get(pre) >= left) {
rangeMap.put(pre, left);
}

rangeMap.subMap(left, true, right, false).clear();
}
}

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

## Time Complexity

addRange(int left, int right): O(log N)
queryRange(int left, int right): O(log N)
removeRange(int left, int right): O(log N) Where
N is total number of ranges in a RangeModule

## Space Complexity

O(N) Where
N is total number of ranges in a RangeModule