题目大意:
题解
啊呀。。。这是昨天的考试题啊。。。直接就粘了。。
与4515: [Sdoi2016]游戏类似,还更简单了一些。
(考场上因为没开long long爆了25分)
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long ll;
inline void read(ll &x){
x=0;char ch;bool flag = false;
while(ch=getchar(),ch<'!');if(ch == '-') ch=getchar(),flag = true;
while(x=10*x+ch-'0',ch=getchar(),ch>'!');if(flag) x=-x;
}
const ll maxn = 100010;
struct Edge{
ll to,next;
}G[maxn<<1];
ll head[maxn],cnt;
void add(ll u,ll v){
G[++cnt].to = v;
G[cnt].next = head[u];
head[u] = cnt;
}
#define v G[i].to
ll fa[maxn],dfn[maxn],top[maxn],dep[maxn],siz[maxn];
ll son[maxn],dfs_clock,seq[maxn],sum[maxn];
void dfs(ll u){
siz[u] = 1;
for(ll i = head[u];i;i=G[i].next){
if(v == fa[u]) continue;
fa[v] = u;
dep[v] = dep[u] + 1;
dfs(v);
siz[u] += siz[v];
if(siz[son[u]] < siz[v]) son[u] = v;
}
}
void dfs(ll u,ll tp){
top[u] = tp;dfn[u] = ++dfs_clock;
seq[dfs_clock] = u;
if(son[u]) dfs(son[u],tp);
for(ll i = head[u];i;i=G[i].next){
if(v == son[u] || v == fa[u]) continue;
dfs(v,v);
}
}
#undef v
inline ll lca(ll u,ll v){
while(top[u] != top[v]){
if(dep[top[u]] < dep[top[v]]) swap(u,v);
u = fa[top[u]];
}return dep[u] < dep[v] ? u : v;
}
struct Node{
Node *ch[2];
ll sum,k,b;
ll dep_sum;
void update(){
dep_sum = ch[0]->dep_sum + ch[1]->dep_sum;
sum = ch[0]->sum + ch[1]->sum;
}
}*null,*root[maxn],*rt;
Node mem[25001001],*it;
inline void init(){
it = mem;
null = it++;null->ch[0] = null->ch[1] = null;
null->sum = null->k = null->b = 0;null->dep_sum = 0;
root[0] = null;
}
inline Node *newNode(){
Node *p = it++;p->ch[0] = p->ch[1] = null;
p->sum = p->k = p->b = p->dep_sum = 0;
return p;
}
ll L,R,K,B,n,T;
Node *change(Node *rt,ll l,ll r){
Node *p = newNode();*p = *rt;
if(L <= l && r <= R){
p->k += K;p->b += B;
p->sum += K*p->dep_sum + B*(r-l+1);
return p;
}ll mid = (l+r) >> 1;
if(L <= mid) p->ch[0] = change(p->ch[0],l,mid);
if(R > mid) p->ch[1] = change(p->ch[1],mid+1,r);
p->update();p->sum += p->dep_sum*p->k + (r-l+1)*p->b;
return p;
}
void change(ll u,ll v,ll a,ll b){
ll lc = lca(u,v);
K = -b;B = (a+dep[u]*b);
while(top[u] != top[lc]){
L = dfn[top[u]];R = dfn[u];
rt = change(rt,1,n);
u = fa[top[u]];
}
L = dfn[lc];R = dfn[u];
rt = change(rt,1,n);
K = b;B -= 2*dep[lc]*b;
while(top[v] != top[lc]){
L = dfn[top[v]];R = dfn[v];
rt = change(rt,1,n);
v = fa[top[v]];
}
L = dfn[lc];R = dfn[v];
if(L == R) return;++L;
rt = change(rt,1,n);
}
ll query(Node *p,ll l,ll r,ll L,ll R){
if(L <= l && r <= R){
return p->sum;
}
ll ret = (sum[min(r,R)] - sum[max(l,L)-1])*p->k + p->b*(min(r,R) - max(l,L) + 1);
ll mid = (l+r) >> 1;
if(L <= mid) ret += query(p->ch[0],l,mid,L,R);
if(R > mid) ret += query(p->ch[1],mid+1,r,L,R);
return ret;
}
inline ll query(ll u,ll v){
ll ret = 0;
while(top[u] != top[v]){
if(dep[top[u]] < dep[top[v]]) swap(u,v);
ret += query(rt,1,n,dfn[top[u]],dfn[u]);
u = fa[top[u]];
}if(dep[u] > dep[v]) swap(u,v);
ret += query(rt,1,n,dfn[u],dfn[v]);
return ret;
}
Node *build(ll l,ll r){
Node *p = newNode();
if(l == r){
p->dep_sum = dep[seq[l]];
p->sum = 0;
return p;
}
ll mid = (l+r) >> 1;
p->ch[0] = build(l,mid);
p->ch[1] = build(mid+1,r);
p->update();return p;
}
char s[10];
int main(){
init();
ll last = 0,total = 0;
ll m;read(n);read(m);
for(ll i=1,u,v;i<n;++i){
read(u);read(v);
add(u,v);add(v,u);
}dfs(1);dfs(1,1);root[0] = build(1,n);
sum[0] = 0;
for(ll i=1;i<=n;++i) sum[i] = sum[i-1] + dep[seq[i]];
rt = root[0];
ll u,v,a,b,w;
while(m--){
scanf("%s",s);
if(*s == 'c'){
read(u);read(v);read(a);read(b);
u ^= last;v ^= last;
change(u,v,a,b);
root[++total] = rt;
}else if(*s == 'q'){
read(u);read(v);
u ^= last;v ^= last;
printf("%lld
",last = query(u,v));
}else{
read(w);w ^= last;
rt = root[w];
}
}
getchar();getchar();
return 0;
}