JZOJ 6813.送信

两个方向:从信到旅行或从旅行到信。

最后都是三维偏序。
树套树过不去。

没什么好说的,写这题解主要是留个 CDQ 板子(

代码:

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#include <cstdio>
#include <algorithm>
using namespace std;

const int BUFF_SIZE = 1 << 20;
char BUFF[BUFF_SIZE],*BB,*BE;
#define gc() (BB == BE ? (BE = (BB = BUFF) + fread(BUFF,1,BUFF_SIZE,stdin),BB == BE ? EOF : *BB++) : *BB++)
template<class T>
inline void read(T &x)
{
x = 0;
char ch = 0,w = 0;
for(;ch < '0' || ch > '9';w |= ch == '-',ch = gc());
for(;ch >= '0' && ch <= '9';x = (x << 3) + (x << 1) + (ch ^ '0'),ch = gc());
w && (x = -x);
}

const int N = 1e5;
const int LG = 18;
int n,m,q;
int to[(N << 1) + 5],pre[(N << 1) + 5],first[N + 5];
inline void add(int u,int v)
{
static int tot = 0;
to[++tot] = v,pre[tot] = first[u],first[u] = tot;
}
int fa[N + 5],dep[N + 5],id[N + 5],rk[N + 5],sz[N + 5];
int son[N + 5],top[N + 5];
int cur[N + 5];
void dfs(int p)
{
int tot = 0,flag;
for(;;)
{
flag = 0;
if(!id[p])
rk[id[p] = ++tot] = p,sz[p] = 1,cur[p] = first[p];
for(register int i = cur[p];i;i = pre[i])
{
cur[p] = pre[i];
if(to[i] ^ fa[p])
{
fa[to[i]] = p,dep[to[i]] = dep[p] + 1,p = to[i],flag = 1;
break;
}
}
if(!flag)
if(fa[p])
{
sz[fa[p]] += sz[p];
if(!son[fa[p]] || sz[p] > sz[son[fa[p]]])
son[fa[p]] = p;
p = fa[p];
}
else
break;
}
}
inline int get(int p,int u)
{
while(top[p] ^ top[u])
{
if(fa[top[p]] == u)
return top[p];
p = fa[top[p]];
}
return son[u];
}
int ans[N + 5],qry_tot,tot;
struct s_operation
{
int op,x,y,w;
} opt[N * 16 + 5],buf[N * 16 + 5];
namespace BIT
{
#define lowbit(x) ((x) & -(x))
int c[N + 5];
inline void update(int x,int k)
{
for(;x <= n;x += lowbit(x))
c[x] += k;
}
inline int query(int x)
{
int ret = 0;
for(;x;x -= lowbit(x))
ret += c[x];
return ret;
}
}
void update(int x,int y,int l,int r)
{
opt[++tot] = (s_operation){0,x,l,1},
opt[++tot] = (s_operation){0,x,r + 1,-1},
opt[++tot] = (s_operation){0,y + 1,l,-1},
opt[++tot] = (s_operation){0,y + 1,r + 1,1};
}
void update(int x,int y)
{
id[x] > id[y] && (swap(x,y),1);
int t = x;
if(id[x] <= id[y] && id[y] < id[x] + sz[x])
x = get(y,x),
id[x] && (update(1,id[x] - 1,id[y],id[y] + sz[y] - 1),1),
id[x] + sz[x] <= n && (update(id[x] + sz[x],n,id[y],id[y] + sz[y] - 1),1);
else
update(id[x],id[x] + sz[x] - 1,id[y],id[y] + sz[y] - 1);
}
void solve(int l,int r)
{
if(l == r)
return ;
int mid = l + r >> 1;
solve(l,mid),solve(mid + 1,r);
int i = l,j = mid + 1,k = l;
while(i <= mid && j <= r)
if(opt[i].x <= opt[j].x)
{
if(!opt[i].op)
BIT::update(opt[i].y,opt[i].w);
buf[k++] = opt[i++];
}
else
{
if(opt[j].op)
ans[-opt[j].w] += BIT::query(opt[j].y);
buf[k++] = opt[j++];
}
while(i <= mid)
{
if(!opt[i].op)
BIT::update(opt[i].y,opt[i].w);
buf[k++] = opt[i++];
}
while(j <= r)
{
if(opt[j].op)
ans[-opt[j].w] += BIT::query(opt[j].y);
buf[k++] = opt[j++];
}
for(register int i = l;i <= mid;++i)
if(!opt[i].op)
BIT::update(opt[i].y,-opt[i].w);
for(register int i = l;i <= r;++i)
opt[i] = buf[i];
}
int main()
{
freopen("letter.in","r",stdin),freopen("letter.out","w",stdout);
read(n),read(m),read(q);
int u,v;
for(register int i = 2;i <= n;++i)
read(u),read(v),add(u,v),add(v,u);
dep[1] = 1,dfs(1);
for(register int i = 1;i <= n;++i)
top[rk[i]] = rk[i] == son[fa[rk[i]]] ? top[fa[rk[i]]] : rk[i];
for(;m;--m)
read(u),read(v),update(u,v);
for(int op;q;--q)
read(op),read(u),read(v),
op == 1 ? (++qry_tot,opt[++tot] = (s_operation){1,id[u],id[v],-qry_tot},opt[++tot] = (s_operation){1,id[v],id[u],-qry_tot},1) : (update(u,v),1);
solve(1,tot);
for(register int i = 1;i <= qry_tot;++i)
printf("%d\n",ans[i]);
}