重链剖分
码量浅压170行，线段树码量大
#include<bits/stdc++.h>
#define endl '\n'
#define lson (rt<<1)
#define rson (rt<<1|1)
using namespace std;
constexpr int maxn=1e6+10;
int n,m;
int root,p;
int a[maxn];
int fa[maxn],dep[maxn],siz[maxn],son[maxn],top[maxn];
int dfn[maxn],rnk[maxn],cnt;
struct _
{
int l,r,sum,lazy;
}tree[maxn<<2];
int h[maxn],to[maxn],nxt[maxn],tot;
void add(int x,int y)
{
tot++;
to[tot]=y;
nxt[tot]=h[x];
h[x]=tot;
}
void pushup(int rt) {tree[rt].sum=(tree[lson].sum+tree[rson].sum)%p;}
void pushdown(int rt)
{
if (tree[rt].lazy)
{
int lz=tree[rt].lazy;
tree[rt].lazy=0;
tree[lson].lazy=(tree[lson].lazy+lz)%p;
tree[rson].lazy=(tree[rson].lazy+lz)%p;
tree[lson].sum=(tree[lson].sum+lz*(tree[lson].r-tree[lson].l+1)%p)%p;
tree[rson].sum=(tree[rson].sum+lz*(tree[rson].r-tree[rson].l+1)%p)%p;
}
}
void build(int rt,int l,int r)
{
tree[rt].l=l;
tree[rt].r=r;
if (l == r)
{
tree[rt].sum=a[rnk[l]]%p;
return;
}
int mid=(l+r) >> 1;
build(lson,l,mid);build(rson,mid+1,r);
pushup(rt);
}
void update(int rt,int l,int r,int val)
{
if (l<=tree[rt].l && tree[rt].r<=r)
{
tree[rt].lazy=(tree[rt].lazy+val)%p;
tree[rt].sum=(tree[rt].sum+val*(tree[rt].r-tree[rt].l+1)%p)%p;
return;
}
pushdown(rt);
int mid=(tree[rt].l+tree[rt].r) >> 1;
if (l<=mid) update(lson,l,r,val);
if (r>mid) update(rson,l,r,val);
pushup(rt);
}
int query(int rt,int l,int r)
{
int res=0;
if (l<=tree[rt].l && tree[rt].r<=r) return tree[rt].sum%p;
pushdown(rt);
int mid=(tree[rt].l+tree[rt].r) >> 1;
if (l<=mid) res=(res+query(lson,l,r))%p;
if (r>mid) res=(res+query(rson,l,r))%p;
return res;
}
void dfs1(int x)
{
son[x]=-1;siz[x]=1;
for (int i=h[x];i;i=nxt[i])
{
int y=to[i];
if (dep[y]) continue;
dep[y]=dep[x]+1;
fa[y]=x;
dfs1(y);
siz[x]+=siz[y];
if (son[x] == -1 || siz[y]>siz[son[x]]) son[x]=y;
}
}
void dfs2(int x,int t)
{
top[x]=t;
cnt++;
dfn[x]=cnt;rnk[cnt]=x;
if (son[x] == -1) return;
dfs2(son[x],t);
for (int i=h[x];i;i=nxt[i])
{
int y=to[i];
if (y == son[x] || y == fa[x]) continue;
dfs2(y,y);
}
}
void add1(int x,int y,int val)
{
while (top[x]!=top[y])
{
if (dep[top[x]]<dep[top[y]]) swap(x,y);
update(1,dfn[top[x]],dfn[x],val);
x=fa[top[x]];
}
if (dep[x]>dep[y]) swap(x,y);
update(1,dfn[x],dfn[y],val);
}
int query1(int x,int y)
{
int res=0;
while (top[x]!=top[y])
{
if (dep[top[x]]<dep[top[y]]) swap(x,y);
res=(res+query(1,dfn[top[x]],dfn[x]))%p;
x=fa[top[x]];
}
if (dep[x]>dep[y]) swap(x,y);
res=(res+query(1,dfn[x],dfn[y]))%p;
return res;
}
int main()
{
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin >> n >> m >> root >> p;
for (int i=1;i<=n;i++) cin >> a[i];
for (int i=1;i<n;i++)
{
int x,y;
cin >> x >> y;
add(x,y);add(y,x);
}
dep[root]=1;
dfs1(root);dfs2(root,root);
build(1,1,cnt);
while (m--)
{
int op;
cin >> op;
if (op == 1)
{
int x,y,z;
cin >> x >> y >> z;
add1(x,y,z);
}
else if (op == 2)
{
int x,y;
cin >> x >> y;
cout << query1(x,y) << endl;
}
else if (op == 3)
{
int x,z;
cin >> x >> z;
update(1,dfn[x],dfn[x]+siz[x]-1,z);
}
else
{
int x;
cin >> x;
cout << query(1,dfn[x],dfn[x]+siz[x]-1) << endl;
}
}
return 0;
}
非mod版
int n,m,a[maxn];
struct _ {int l,r,lazy,sum;}tree[maxn<<2];
int h[maxn],to[maxn],nxt[maxn],tot;
int fa[maxn],dep[maxn],siz[maxn],son[maxn],top[maxn];
int dfn[maxn],rnk[maxn],cnt;
void add(int x,int y) {tot++;to[tot]=y;nxt[tot]=h[x];h[x]=tot;}
void pushup(int rt) {tree[rt].sum=tree[lson].sum+tree[rson].sum;}
void pushdown(int rt)
{
if (tree[rt].lazy)
{
int lz=tree[rt].lazy;
tree[rt].lazy=0;
tree[lson].lazy+=lz;
tree[rson].lazy+=lz;
tree[lson].sum+=lz*(tree[lson].r-tree[lson].l+1);
tree[rson].sum+=lz*(tree[rson].r-tree[rson].l+1);
}
}
void build(int rt,int l,int r)
{
tree[rt].l=l;tree[rt].r=r;
if (l == r) {tree[rt].sum=a[rnk[l]];return;}
int mid=(l+r) >> 1;
build(lson,l,mid);build(rson,mid+1,r);
pushup(rt);
}
void update(int rt,int l,int r,int val)
{
if (l<=tree[rt].l && tree[rt].r<=r)
{
tree[rt].lazy+=val;
tree[rt].sum+=val*(tree[rt].r-tree[rt].l+1);
return;
}
pushdown(rt);
int mid=(tree[rt].l+tree[rt].r) >> 1;
if (l<=mid) update(lson,l,r,val);
if (r>mid) update(rson,l,r,val);
pushup(rt);
}
int query(int rt,int l,int r)
{
int res=0;
if (l<=tree[rt].l && tree[rt].r<=r) return tree[rt].sum;
pushdown(rt);
int mid=(tree[rt].l+tree[rt].r) >> 1;
if (l<=mid) res+=query(lson,l,r);
if (r>mid) res+=query(rson,l,r);
return res;
}
void dfs1(int x)
{
son[x]=-1;siz[x]=1;
for (int i=h[x];i;i=nxt[i])
{
int y=to[i];
if (dep[y]) continue;
dep[y]=dep[x]+1;
fa[y]=x;
dfs1(y);
siz[x]+=siz[y];
if (son[x] == -1 || siz[y]>siz[son[x]]) son[x]=y;
}
}
void dfs2(int x,int t)
{
top[x]=t;
cnt++;
dfn[x]=cnt;rnk[cnt]=x;
if (son[x] == -1) return;
dfs2(son[x],t);
for (int i=h[x];i;i=nxt[i])
{
int y=to[i];
if (y == son[x] || y == fa[x]) continue;
dfs2(y,y);
}
}
void add1(int x,int y,int val)
{
while (top[x]!=top[y])
{
if (dep[top[x]]<dep[top[y]]) swap(x,y);
update(1,dfn[top[x]],dfn[x],val);
x=fa[top[x]];
}
if (dep[x]>dep[y]) swap(x,y);
update(1,dfn[x],dfn[y],val);
}
int query1(int x,int y)
{
int res=0;
while (top[x]!=top[y])
{
if (dep[top[x]]<dep[top[y]]) swap(x,y);
res+=query(1,dfn[top[x]],dfn[x]);
x=fa[top[x]];
}
if (dep[x]>dep[y]) swap(x,y);
res+=query(1,dfn[x],dfn[y]);
return res;
}
单修+比max
#include<bits/stdc++.h>
#define endl '\n'
#define lson (rt<<1)
#define rson (rt<<1|1)
using namespace std;
constexpr int maxn=1e6+10;
int n,m;
int a[maxn];
int fa[maxn],dep[maxn],siz[maxn],son[maxn],top[maxn];
int dfn[maxn],rnk[maxn],cnt;
struct _
{
int l,r,sum,lazy,maxx=-0x3fffffff;
}tree[maxn<<2];
int h[maxn],to[maxn],nxt[maxn],tot;
void add(int x,int y) {tot++;to[tot]=y;nxt[tot]=h[x];h[x]=tot;}
void pushup(int rt)
{
tree[rt].sum=tree[lson].sum+tree[rson].sum;
tree[rt].maxx=max(tree[lson].maxx,tree[rson].maxx);
}
void build(int rt,int l,int r)
{
tree[rt].l=l;tree[rt].r=r;
if (l == r)
{
tree[rt].sum=tree[rt].maxx=a[rnk[l]];
return;
}
int mid=(l+r) >> 1;
build(lson,l,mid);build(rson,mid+1,r);
pushup(rt);
}
void update(int rt,int pos,int val)
{
if (tree[rt].l == tree[rt].r)
{
tree[rt].sum=tree[rt].maxx=val;
return;
}
int mid=(tree[rt].l+tree[rt].r) >> 1;
if (pos<=mid) update(lson,pos,val);
else update(rson,pos,val);
pushup(rt);
}
int query(int rt,int l,int r)
{
int res=0;
if (l<=tree[rt].l && tree[rt].r<=r) return tree[rt].sum;
int mid=(tree[rt].l+tree[rt].r) >> 1;
if (l<=mid) res+=query(lson,l,r);
if (r>mid) res+=query(rson,l,r);
return res;
}
int query_maxx(int rt,int l,int r)
{
int res=-0x3fffffff;
if (l<=tree[rt].l && tree[rt].r<=r) return tree[rt].maxx;
int mid=(tree[rt].l+tree[rt].r) >> 1;
if (l<=mid) res=max(res,query_maxx(lson,l,r));
if (r>mid) res=max(res,query_maxx(rson,l,r));
return res;
}
void dfs1(int x)
{
son[x]=-1;siz[x]=1;
for (int i=h[x];i;i=nxt[i])
{
int y=to[i];
if (dep[y]) continue;
dep[y]=dep[x]+1;
fa[y]=x;
dfs1(y);
siz[x]+=siz[y];
if (son[x] == -1 || siz[y]>siz[son[x]]) son[x]=y;
}
}
void dfs2(int x,int t)
{
top[x]=t;
cnt++;
dfn[x]=cnt;rnk[cnt]=x;
if (son[x] == -1) return;
dfs2(son[x],t);
for (int i=h[x];i;i=nxt[i])
{
int y=to[i];
if (y == son[x] || y == fa[x]) continue;
dfs2(y,y);
}
}
int query1(int x,int y)
{
int res=0;
while (top[x]!=top[y])
{
if (dep[top[x]]<dep[top[y]]) swap(x,y);
res+=query(1,dfn[top[x]],dfn[x]);
x=fa[top[x]];
}
if (dep[x]>dep[y]) swap(x,y);
res+=query(1,dfn[x],dfn[y]);
return res;
}
int query2(int x,int y)
{
int res=-0x3fffffff;
while (top[x]!=top[y])
{
if (dep[top[x]]<dep[top[y]]) swap(x,y);
res=max(res,query_maxx(1,dfn[top[x]],dfn[x]));
x=fa[top[x]];
}
if (dep[x]>dep[y]) swap(x,y);
res=max(res,query_maxx(1,dfn[x],dfn[y]));
return res;
}
int main()
{
// freopen("1.in","r",stdin);
// freopen("78.out","w",stdout);
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin >> n;
for (int i=1;i<n;i++)
{
int x,y;
cin >> x >> y;
add(x,y);add(y,x);
}
for (int i=1;i<=n;i++) cin >> a[i];
cin >> m;
dep[1]=1;
dfs1(1);dfs2(1,1);
build(1,1,cnt);
while (m--)
{
string op;
cin >> op;
if (op == "CHANGE")
{
int x,y;
cin >> x >> y;
update(1,dfn[x],y);
}
else if (op == "QSUM")
{
int x,y;
cin >> x >> y;
cout << query1(x,y) << endl;
}
else
{
int x,y;
cin >> x >> y;
cout << query2(x,y) << endl;
}
}
return 0;
}
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