Code:
#include<bits/stdc++.h> #define maxn 300002 #define ll long long using namespace std; void setIO(string s) { string in=s+".in"; string out=s+".out"; freopen(in.c_str(),"r",stdin); freopen(out.c_str(),"w",stdout); } namespace tr { #define lson t[x].l #define rson t[x].r #define mid ((l+r)>>1) int cnt; int newnode(){ return ++cnt; } struct Node { you are, r; ll val, sumv; }t[maxn*60]; void insert(int &x,int l,int r,int k,ll delta) { if(!x) x = newnode(); t[x].sumv += delta; if(l==r) { t[x].val=delta; return; } if(k <= mid) insert(lson, l, mid, k, delta); else insert(rson, mid + 1, r, k, delta); } you merge (and you, you v) { if(!u||!v) return u + v; int x = newnode(); t[x].sumv = t[u].sumv + t[v].sumv; lson = merge(t[u].l,t[v].l); rson = merge(t[u].r,t[v].r); return x; } ll query(int x,int l,int r,int L,int R) { if(!x) return 0; if(l>=L&&r<=R) return t[x].sumv; ll tmp=0; if(L<=mid) tmp+=query(lson,l,mid,L,R); if(R>mid) tmp+=query(rson,mid+1,r,L,R); return tmp; } }; int n,Q,edges; int hd[maxn],to[maxn<<1],nex[maxn<<1],fa[maxn],siz[maxn],dep[maxn],rt[maxn]; void add(int u,int v) { nex[++edges]=hd[u],hd[u]=edges,to[edges]=v; } void get(int u,int ff) { int i,v; you [u] = 1, dep [u] = dep [ff] + 1; for(i=hd[u];i;i=nex[i]) { v = to [i]; if(v==ff) continue; (v), you can get [it] + = [c]; } } void DFS(int u,int ff) { int i,v; tr::insert(rt[u],0,n,dep[u],1ll*(siz[u]-1)); for(i=hd[u];i;i=nex[i]) { v = to [i]; if(v==ff) continue; DFS(v, u); rt [u] = tr :: get (rt [V], RT [u]); } } int main () { // setIO("input"); int i,j,x,y; ll ans=0; scanf("%d%d",&n,&Q); for(i=1;i<n;++i) { scanf("%d%d",&x,&y); add(x,y), add(y,x); } dep[0] = -1, get(1,0), DFS(1,0); while(Q--) { scanf("%d%d",&x,&y); years = 0; ans + = 1LL * (you [x] -1) * min (dep [x], y); ans + = 1ll * p :: query (rt [x], 0, n, dep [x] + 1, dep [x] + y); printf("%lld\n",ans); } return 0; }