树状数组模板
#define lowbit(x) (x&(-x))
int c[Max], n;//n为元素个数
void add(int x, int v)//单点给元素+v
{for (int i = x;i <= n;i += lowbit(i))c[i] += v;}
int que(int x)//询问前x元素的总和
{
int ans = 0;
for (int i = x;i != 0;i -= lowbit(i))ans += c[i];
return ans;
}
