Dynamic segment tree leetcode seven hundred and fifteen

private Map<Integer, Integer> tree;// Line segment tree , Represents the value of a node 
    private Map<Integer, Integer> lazy;// Lazy mark 
    private int N;
    public RangeModule() {
        tree = new HashMap<Integer, Integer>();
        lazy = new HashMap<Integer, Integer>();
        N= (int)1e9;
    }
    // Interval modification ( increase )
    public void update(int l,int r,int val){
        if(l>r) return;
        update(l,r,1,N,1,val);
    }
    private void update( int l, int r,int curl, int curr, int node,int val) {
        // Interval no intersection 
        if (curl>r||curr<l)
            return;
        // The current interval is within the target interval 
        if (l<=curl&&curr<=r) {
            int sum=tree.getOrDefault(node, 0);// Current interval and 
            if(val==1&&sum<(curr-curl+1)*val){// Some nodes in the current interval are not tracked 
                tree.put(node,(curr-curl+1)*val);// Update current node 
                if(curl<curr) lazy.put(node, 1);
            }else if(val==-1&&sum>0) {// There are tracked nodes in the current interval 
                tree.put(node, 0);// Update current node 
                if (curl < curr) lazy.put(node, -1);
            }
        } else {// There is an intersection between the current interval and the target interval 
            int mid = (curl + curr) >> 1;
            if(lazy.getOrDefault(node,0)!=0)
                pushDown(node,curr-curl+1);
            update( l, r, curl, mid,2 * node,val);
            update(l, r, mid+1, curr, 2 * node + 1,val);
            tree.put(node, tree.getOrDefault(2 * node, 0)+tree.getOrDefault(2 * node + 1, 0));
        }
    }
    // Pass the tag to the next level 
    private void pushDown(int node,int len){
        int _lazy=lazy.get(node);
        int sum1=tree.getOrDefault(node*2,0);
        int sum2=tree.getOrDefault(node*2+1,0);
        if(_lazy==1){
            // Untracked nodes exist in the interval 
            if(sum1<(len-len/2)*_lazy){
                lazy.put(node*2,1);
                tree.put(node*2,(len-len/2)*_lazy);
            }
            if(sum2<len/2*_lazy){
                lazy.put(node*2+1,1);
                tree.put(node*2+1,len/2*_lazy);
            }
        }else{
            // There are tracked nodes in the interval 
            if(sum1>0){
                lazy.put(node*2,-1);
                tree.put(node*2,0);
            }
            if(sum2>0){
                lazy.put(node*2+1,-1);
                tree.put(node*2+1,0);
            }
        }
        lazy.put(node,0);
    }
    // Interval query 
    public int query(int l,int r){
        if(l>r) return -1;
        return query(l,r,1,N,1);
    }
    private int query(int l,int r,int curl,int curr,int node){
        // Not in the target range 
        if(curl>r||curr<l)
            return 0;
        // In the target range 
        if(l<=curl&&curr<=r)
            return tree.getOrDefault(node,0);
        // Some have intersections , Split interval processing 
        int mid=(curl+curr)>>1;
        if(lazy.getOrDefault(node,0)!=0)
            pushDown(node,curr-curl+1);
        return  query(l,r,curl,mid,node*2)+query(l,r,mid+1,curr,node*2+1);
    }
 
    public void addRange(int left, int right) {
        update( left, right - 1, 1);
    }
    public boolean queryRange(int left, int right) {
        return query(left, right - 1) == right - left;
    }
    public void removeRange(int left, int right) {
        update(left, right - 1, -1);
    }