树状数组 （模板）

struct szsz{int c[maxn];int lowbit(int x){return x&(-x);} int getadd(int x){int ans=0;while(x>0){ans+=c[x];x-=lowbit(x);}return ans;}void update(int x,int n,int d){while(x<=n){c[x]+=d;x+=lowbit(x); } }} T;