洛谷 P3384 【模板】树链剖分（指针版）

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
typedef long long ll;
const int MAXN = 1e6 + 5;
ll n,a,b,c,firs[MAXN],nex[MAXN],cnt = 0,q,r,m,num2[MAXN];
char s[233];
struct dd
{
ll f,t;
}rad[MAXN];
void build(ll f,ll t)
{
rad[++cnt] = (dd){f,t};
nex[cnt] = firs[f];
firs[f] = cnt;
}
struct zt
{
ll sum,jia,sz;
zt *lift,*right;
}tree[MAXN];
ll num = 0;
void build_tree(zt *root,ll l,ll r)
{
root->sum = root->jia = 0;root->sz = r - l + 1;
if(l == r)
return;
root->lift = &tree[++num];
root->right = &tree[++num];
ll mid = l + r >> 1;
build_tree(root->lift,l,mid);
build_tree(root->right,mid + 1,r);
}
ll fa[MAXN],sz[MAXN],son[MAXN],deep[MAXN];
void dfs1(ll x,ll f)
{
fa[x] = f;sz[x] = 1;deep[x] = deep[f] + 1;
for(int i = firs[x];i != -1;i = nex[i])
{
ll v = rad[i].t;
if(v != f)
{
dfs1(v,x);
sz[x] += sz[v];
if(!son[x]||sz[son[x]] < sz[v])
son[x] = v;
}
}
}
ll top[MAXN],intu[MAXN],ji = 0,ed[MAXN];
void dfs2(ll x,ll topx)
{
top[x] = topx;
intu[x] = ++ji;
ed[x] = x;
if(!son[x]) return;
dfs2(son[x],topx);
ed[x] = ed[son[x]];
for(int i = firs[x];i != -1;i = nex[i])
{
ll v = rad[i].t;
if(v != fa[x]&&v != son[x])
dfs2(v,v),ed[x] = ed[v];
}
}
void hs(zt *root)
{
root->sum = root->lift->sum + root->right->sum;
}
void xf(zt *root)
{
root->lift->jia += root->jia;
root->right->jia += root->jia;
root->lift->sum += root->lift->sz * root->jia;
root->right->sum += root->right->sz * root->jia;
root->jia = 0;
}
void change(zt *root,ll l,ll r,ll ql,ll qr,ll x)
{
if(l >= ql&&qr >= r)
{
root->jia += x;
root->sum += root->sz * x;
return;
}
if(root->jia)
xf(root);
ll mid = l + r >> 1;
if(ql <= mid)   change(root->lift,l,mid,ql,qr,x);
if(qr > mid)    change(root->right,mid + 1,r,ql,qr,x);
hs(root);
}
void swap(ll &a,ll &b)
{
a^=b^=a^=b;
}
ll ask_sum(zt *root,ll l,ll r,ll ql,ll qr)
{
if(l >= ql&&qr >= r)
return root->sum;
if(root->jia)
xf(root);
ll mid = l + r >> 1,ans = 0;
if(ql <= mid)   ans = ask_sum(root->lift,l,mid,ql,qr);
if(qr > mid)    ans += ask_sum(root->right,mid + 1,r,ql,qr);
return ans;
}
ll find_sum(ll a,ll b)
{
ll at = top[a],bt = top[b],ans = 0;
while(at != bt)
{
if(deep[at] < deep[bt]) swap(at,bt),swap(a,b);
ans += ask_sum(tree,1,n,intu[at],intu[a]);
a = fa[at],at = top[a];
}
if(deep[a] > deep[b])   swap(a,b);
ans += ask_sum(tree,1,n,intu[a],intu[b]);
return ans;
}
void find_change(ll a,ll b,ll x)
{
ll at = top[a],bt = top[b];
while(at != bt)
{
if(deep[at] < deep[bt]) swap(at,bt),swap(a,b);
change(tree,1,n,intu[at],intu[a],x);
a = fa[at],at = top[a];
}
if(deep[a] > deep[b])   swap(a,b);
change(tree,1,n,intu[a],intu[b],x);
}
int main()
{
scanf("%lld%lld%lld%lld",&n,&q,&r,&m);
build_tree(tree,1,n);
for(int i = 1;i <= n;i ++)
firs[i] = -1;
for(int i = 1;i <= n;i ++)
scanf("%lld",&num2[i]);
for(int i = 1;i < n;i ++)
{
scanf("%lld%lld",&a,&b);
build(a,b);
build(b,a);
}
dfs1(r,0);
dfs2(r,r);
for(int i = 1;i <= n;i ++)
change(tree,1,n,intu[i],intu[i],num2[i]);
for(int i = 1;i <= q;i ++)
{
scanf("%lld",&a);
if(a == 1)  scanf("%lld%lld%lld",&a,&b,&c),find_change(a,b,c);
else if(a == 2) scanf("%lld%lld",&b,&c),cout<<find_sum(b,c) % m<<'\n';
else if(a == 3) scanf("%lld%lld",&b,&c),change(tree,1,n,intu[b],intu[ed[b]],c);
else scanf("%lld",&b),cout<<ask_sum(tree,1,n,intu[b],intu[ed[b]]) % m<<'\n';
}
}