【luogu P3258 [JLOI2014]松鼠的新家】 题解

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#define ll long long
using namespace std;
const int maxn = 500010;
ll ans[maxn], son[maxn], deep[maxn], size[maxn], fa[maxn], top[maxn], seg[maxn], num, n, m, path[maxn];
struct edge{
ll to, next;
}e[maxn<<2];
{
}
class Segment_Tree{
public:
#define lson l, mid, rt<<1
#define rson mid+1, r, rt<<1|1
ll tree[maxn<<2], lazy[maxn<<2];
void build(ll l, ll r, ll rt)
{
if(l == r)
{
tree[rt] = 0;
return;
}
ll mid = (l + r) >> 1;
build(lson);
build(rson);
PushUP(rt);
}
void update(ll left, ll right, ll add, ll l, ll r, ll rt)
{
if(left <= l && right >= r)
{
tree[rt] += (r - l + 1) * add;
return;
}
ll mid = (l + r) >> 1;
PushDOWN(l, r, rt);
if(left <= mid) update(left, right, add, lson);
if(right > mid) update(left, right, add, rson);
PushUP(rt);
}
ll query(ll left, ll right, ll l, ll r, ll rt)
{
ll res = 0;
if(left <= l && right >= r)
{
return tree[rt];
}
ll mid = (l + r) >> 1;
PushDOWN(l, r, rt);
if(left <= mid) res += query(left, right, lson);
if(right > mid) res += query(left, right, rson);
return res;
}
private:
void PushUP(ll rt)
{
tree[rt] = tree[rt<<1] + tree[rt<<1|1];
}
void PushDOWN(ll l, ll r, ll rt)
{
ll mid = (l + r) >> 1;
if(lazy[rt])
{
lazy[rt<<1] += lazy[rt];
lazy[rt<<1|1] += lazy[rt];
tree[rt<<1] += (mid-l+1)*lazy[rt];
tree[rt<<1|1] += (r-mid)*lazy[rt];
lazy[rt] = 0;
}
}
}T;
void dfs1(ll u, ll f, ll d)
{
ll maxson = -1;
size[u] = 1;
deep[u] = d;
fa[u] = f;
for(ll i = head[u]; i != -1; i = e[i].next)
{
ll v = e[i].to;
if(f != v)
{
dfs1(v, u, d+1);
size[u] += size[v];
if(size[v] > maxson) son[u] = v, maxson = size[v];
}
}
}
void dfs2(ll u, ll t)
{
seg[u] = ++num;
top[u] = t;
if(!son[u]) return;
dfs2(son[u], t);
for(ll i = head[u]; i != -1; i = e[i].next)
{
ll v = e[i].to;
if(v == son[u] || v == fa[u]) continue;
dfs2(v, v);
}
}
ll LCA(ll x, ll y)
{
while(top[x] != top[y])
{
if(deep[top[x]] < deep[top[y]]) swap(x, y);
x = fa[top[x]];
}
return deep[x] < deep[y] ? x : y;
}
ll Qson(ll x)
{
ll res = 0;
res += T.query(seg[x], seg[x]+size[x]-1, 1, n, 1);
return res;
}
void Updson(ll x, ll y)
{
T.update(seg[x], seg[x]+size[x]-1, y, 1, n, 1);
}
ll Qrange(ll x, ll y)
{
ll res = 0;
while(top[x] != top[y])
{
if(deep[top[x]] < deep[top[y]]) swap(x, y);
res += T.query(seg[top[x]], seg[x], 1, n, 1);
x = fa[top[x]];
}
if(deep[x] < deep[y]) swap(x, y);
res += T.query(seg[y], seg[x], 1, n, 1);
return res;
}
void Updrange(ll x, ll y, ll z)
{
while(top[x] != top[y])
{
if(deep[top[x]] < deep[top[y]]) swap(x, y);
T.update(seg[top[x]], seg[x], z, 1, n, 1);
x = fa[top[x]];
}
if(deep[x] < deep[y]) swap(x, y);
T.update(seg[y], seg[x], z, 1, n, 1);
}
int main()
{
scanf("%lld%lld",&n,&path[1]);
for(ll i = 2; i <= n; i++)
{
scanf("%lld",&path[i]);
ans[path[i]]--;
}
for(ll i = 1; i <= n-1; i++)
{
ll u, v;
scanf("%lld%lld",&u,&v);
}
dfs1(1, 0, 1); dfs2(1, 1);
T.build(1, n, 1);
for(ll i = 2; i <= n; i++)
{
Updrange(path[i], path[i-1], 1);
}
for(ll i = 1; i <= n; i++) ans[i] += Qrange(i, i);
for(ll i = 1; i <= n; i++)
{
printf("%lld\n",ans[i]);
}
return 0;
}

posted @ 2018-10-30 15:54  Misaka_Azusa  阅读(86)  评论(0编辑  收藏
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