线段树模板

Posted 2021-02-11 nublity

void pushdown(int l, int r, int rt)
{
    if (lazy[rt])
    {
        sum[rt << 1] += l * lazy[rt];
        sum[(rt << 1) + 1] += r * lazy[rt];
        lazy[rt << 1] += lazy[rt];
        lazy[(rt << 1) + 1] += lazy[rt];
        lazy[rt] = 0;
    }
}
void build(int l, int r, int rt)
{
    if (l == r)
    {
        sum[rt] = tmp[l];
        return;
    }
    int mid = (l + r) >> 1;
    build(l, mid, rt << 1);
    build(mid + 1, r, (rt << 1) + 1);
    sum[rt] = sum[rt << 1] + sum[(rt << 1) + 1];
}
void update(int l, int r, int rt, int l1, int r1, int v)
{
    if (l1 <= l && r <= r1)
    {
        sum[rt] += v * (r - l + 1);
        lazy[rt] += v;
        return;
    }
    int mid = (l + r) >> 1;
    pushdown(mid - l + 1, r - mid, rt);
    if (l1 <= mid)
        update(l, mid, rt << 1, l1, r1, v);
    if (r1 > mid)
        update(mid + 1, r, (rt << 1) + 1, l1, r1, v);
    sum[rt] = sum[rt << 1] + sum[(rt << 1) + 1];
}
int query(int l, int r, int rt, int l1, int r1)
{
    if (l1 <= l && r <= r1)
        return (ll)sum[rt];
    int mid = (l + r) >> 1;
    int ret = 0;
    pushdown(mid - l + 1, r - mid, rt);
    if (l1 <= mid)
        ret += query(l, mid, rt << 1, l1, r1);
    if (r1 > mid)
        ret += query(mid + 1, r, (rt << 1) + 1, l1, r1);
    sum[rt] = sum[rt << 1] + sum[(rt << 1) + 1];
    return ret;
}