RMQ с прибавлением на отрезке. Динамическая структура.

#include <stdio.h>
#include <iostream>

using namespace std;

#define MAX_N 100000
#define INFIN 1000000

int N;
int Ar[MAX_N];

struct rmq {
    int Max;
    int Add;
    int L, R;
    rmq *lt, *rt;
    rmq() {
        Max = 0;
        lt = rt = NULL;
    }
    rmq(int l, int r) {
        L = l, R = r;
        Add = 0;
        if (l == r) {
            Max = Ar[l];
            lt = rt = NULL;
            return;
        }
        int m = (l + r) / 2;
        lt = new rmq(l , m);
        rt = new rmq(m + 1, r);
        Max = max(lt->Max, rt->Max);
    }
    int getMax(int l, int r) {
        if (r < L || R < l)
            return -INFIN;
        if (l <= L && R <= r)
            return Max + Add;
        return max(lt->getMax(l,r), rt->getMax(l,r)) + Add;
    }
    void change(int pos, int val) {
        if (L > pos || R < pos)
            return;
        if (L == R) {
            Max = val + Add;
            return;
        }
        lt->change(pos, val), rt->change(pos, val);
        Max = max(lt->Max, rt->Max);
    }
    void add(int l, int r, int a) {
        if (r < L || R < l)
            return;
        if (l <= L && R <= r)
            Add += a;
        else
            lt->add(l,r,a), rt->add(l,r,a);
    }
    ~rmq() {
        if (lt)
            delete lt;
        if (rt)
            delete rt;
    }
};

int main () {
    rmq *root = new rmq(0, N -1);
    delete root;
    return 0;
}