//改变序列参数,动态查询一段序列和:树状数组、线段树
//动态查询一段序列最大值或最小值:线段树
//树状数组
int lowbit(int x)
{
return x & -x;
}
void add(int x, int v)
{
for(int i = x; i <= n; i += lowbit(i)) tr[i] += v;
}
int sum(int x)
{
int res = 0;
for(int i = x; i > 0; i -= lowbit(i)) res += tr[i];
return res;
}
//线性数组有四个模板函数 pushup、build、query、modify
struct tr
{
int l, r;
int sum;
}tr[N * 4];
int w[N], n, m;
void pushup(int u)
{
tr[u].sum = tr[2 *u].sum +tr[2 * u + 1].sum;
}
void build(int u, int l, int r)
{
if(l == r) tr[u] = {l, r, w[r]};
else
{
tr[u] = {l, r};
int mid = l + r >> 1;
build(2 * u, l, mid), build(2 * u + 1, mid + 1, r);
pushup(u);
}
}
void modify(int u, int x, int v)
{
if(tr[u].l == tr[u].r) tr[u].sum += v;
else
{
int mid = tr[u].l +tr[u].r >> 1;
if(x <= mid) modify(2 * u, x, v);
if(x > mid) modify(2 * u + 1, x, v);
pushup(u);
}
}
int query(int u, int l, int r)
{
if(l <= tr[u].l && r >= tr[u].r) return tr[u].sum;
int mid = tr[u].l + tr[u].r >> 1;
int sum = 0;
if(l <= mid) sum += query(2 * u, l, r);
if(r > mid) sum += query(2 * u + 1, l, r);
return sum;
}