struct node { int val; node* c[2]; node() { val = 0; c[0] = c[1] = 0; } node* get_c(int i) { return (!c[i] ? c[i] = new node : c[i]); } void update(int x, int v, int l, int r) { if (l == r) val += v; else { int m = (l + r) >> 1; x <= m ? get_c(0)->update(x, v, l, m) : get_c(1)->update(x, v, m + 1, r); val = (c[0] ? c[0]->val : 0) + (c[1] ? c[1]->val : 0); } } int query(int a, int b, int l, int r) { if (a > r || b < l) return 0; if (a <= l && b >= r) return val; int m = (l + r) >> 1; return (c[0] ? c[0]->query(a, b, l, m) : 0) + (c[1] ? c[1]->query(a, b, m + 1, r) : 0); } };