yintaocheng @ 2023-11-13 15:53:47
#include<bits/stdc++.h>
#define int long long
using namespace std;
inline int read()
{
char c;
bool f=false;
int s=0;
c=getchar();
while(!isdigit(c))
{
f=(c=='-');
c=getchar();
}
while(isdigit(c))
{
s=(s<<3)+(s<<1)+c-'0';
c=getchar();
}
return f?-s:s;
}
void write(int x)
{
if(x<0)
{
putchar('-');
x=-x;
}
if(x>9)
{
write(x/10);
}
putchar(x%10+'0');
}
const int N=100010;
int n,m,r,mod;
struct Edge
{
int to,nxt;
}edge[N<<1];
int head[N<<1],cnt=0;
inline void init()
{
for(int i=0;i<2*N;i++)
{
edge[i].to=-1;
}
memset(head,-1,sizeof(head));
cnt=0;
}
inline void addedge(int u,int v)
{
edge[cnt].to=v;
edge[cnt].nxt=head[u];
head[u]=cnt++;
}
int w[N],w_new[N];
int tree[N<<2],tag[N<<2];
inline void addtag(int p,int pl,int pr,int d)
{
tag[p]+=d;
tree[p]+=(pr-pl+1)*d;
tree[p]%=mod;
}
inline int ls(int x)
{
return x<<1;
}
inline int rs(int x)
{
return x<<1|1;
}
inline void push_up(int p)
{
tree[p]=(tree[ls(p)]+tree[rs(p)])%mod;
}
inline void push_down(int p,int pl,int pr)
{
if(tag[p])
{
int mid=(pl+pr)>>1;
addtag(ls(p),pl,mid,tag[p]);
addtag(rs(p),mid+1,pr,tag[p]);
tag[p]=0;
}
}
void build(int p,int pl,int pr)
{
tag[p]=0;
if(pl==pr)
{
tree[p]=w_new[pl];
tree[p]%=mod;
return;
}
int mid=(pl+pr)>>1;
build(ls(p),pl,mid);
build(rs(p),mid+1,pr);
push_up(p);
}
void update(int p,int pl,int pr,int d,int l,int r)
{
if(l<=pl&&pr<=r)
{
addtag(p,pl,pr,d);
return;
}
push_down(p,pl,pr);
int mid=(pl+pr)>>1;
if(l<=mid)
update(ls(p),pl,mid,d,l,r);
if(r>=mid+1)
update(rs(p),mid+1,pr,d,l,r);
push_up(p);
}
int query(int p,int pl,int pr,int l,int r)
{
if(l<=pl&&pr<=r)return tree[p]%=mod;
push_down(p,pl,pr);
int res=0;
int mid=(pl+pr)>>1;
if(l<=mid)
res+=query(ls(p),pl,mid,l,r);
if(r>mid)
res+=query(rs(p),mid+1,pr,l,r);
return res;
}
int son[N],id[N],fa[N],dep[N],siz[N],top[N];
void dfs1(int x,int father)
{
dep[N]=dep[father]+1;
fa[x]=father;
siz[x]=1;
for(int i=head[x];~i;i=edge[i].nxt)
{
int y=edge[i].to;
if(y!=father)
{
fa[y]=x;
dfs1(y,x);
siz[x]+=siz[y];
if(!son[x]||siz[son[x]]<siz[y])
son[x]=y;
}
}
}
int num=0;
void dfs2(int x,int topx)
{
id[x]=++num;
w_new[num]=w[x];
top[x]=topx;
if(!son[x])
return;
dfs2(son[x],topx);
for(int i=head[x];~i;i=edge[i].nxt)
{
int y=edge[i].to;
if(y!=fa[x]&&y!=son[x])
dfs2(y,y);
}
}
inline void update_range(int x,int y,int z)
{
int ans=0;
while(top[x]!=top[y])
{
if(dep[top[x]]<dep[top[y]])
swap(x,y);
update(1,1,n,z,id[top[x]],id[x]);
x=fa[top[x]];
}
if(dep[x]>dep[y])
swap(x,y);
update(1,1,n,z,id[x],id[y]);
}
inline int query_range(int x,int y)
{
int ans=0;
while(top[x]!=top[y])
{
if(dep[top[x]]<dep[top[y]])
swap(x,y);
ans+=query(1,1,n,id[top[x]],id[x]);
ans%=mod;
x=fa[top[x]];
}
if(dep[x]>dep[y])
swap(x,y);
ans+=query(1,1,n,id[x],id[y]);
return ans%mod;
}
inline void update_tree(int x,int k)
{
update(1,1,n,k,id[x],id[x]+siz[x]-1);
}
inline int query_tree(int x)
{
return query(1,1,n,id[x],id[x]+siz[x]-1)%mod;
}
signed main()
{
init();
n=read();
m=read();
r=read();
mod=read();
for(int i=1;i<=n;i++)
w[i]=read();
for(int i=1;i<n;i++)
{
int u=read(),v=read();
addedge(u,v);
addedge(v,u);
}
dfs1(r,0);
dfs2(r,r);
build(1,1,n);
while(m--)
{
int k,x,y,z;
k=read();
if(k==1)
{
x=read();
y=read();
z=read();
update_range(x,y,z);
}
else if(k==2)
{
x=read();
y=read();
write(query_range(x,y));
putchar('\n');
}
else if(k==3)
{
x=read();
y=read();
update_tree(x,y);
}
else
{
x=read();
write(query_tree(x));
putchar('\n');
}
}
return 0;
}
by A_Cabbage @ 2023-11-13 16:27:33
@yintaocheng
你的dfs1函数里:
dep[N]=dep[father]+1;
by yintaocheng @ 2023-11-13 16:32:25
@A_Cabbage 又多一个逆天笔误