LOJ#3036. 「JOISC 2019 Day3」指定城市
一个点的可以dp出来
两个点也可以dp出来
后面的就是在两个点的情况下选一条最长的链加进去，用线段树维护即可
#include <bits/stdc++.h>
#define fi first
#define se second
#define pii pair<int,int>
#define mp make_pair
#define pb push_back
#define space putchar(' ')
#define enter putchar('
')
#define eps 1e-10
#define MAXN 200005
#define ba 47
//#define ivorysi
using namespace std;
typedef long long int64;
typedef unsigned int u32;
typedef double db;
template<class T>
void read(T &res) {
res = 0;T f = 1;char c = getchar();
while(c < '0' || c > '9') {
if(c == '-') f = -1;
c = getchar();
}
while(c >= '0' && c <= '9') {
res = res * 10 +c - '0';
c = getchar();
}
res *= f;
}
template<class T>
void out(T x) {
if(x < 0) {x = -x;putchar('-');}
if(x >= 10) {
out(x / 10);
}
putchar('0' + x % 10);
}
struct node {
int to,next;int64 val;
}E[MAXN * 2];
int head[MAXN],sumE,N;
int64 ans[MAXN],all;
void add(int u,int v,int c) {
E[++sumE].to = v;
E[sumE].next = head[u];
E[sumE].val = c;
head[u] = sumE;
}
namespace one {
int64 dis[2][MAXN],fir;
void dfs(int u,int fa) {
for(int i = head[u] ; i ; i = E[i].next) {
int v = E[i].to;
if(v == fa) {dis[1][u] = dis[1][fa] + E[i].val;fir += E[i].val;}
else dis[0][v] = dis[0][u] + E[i].val;
}
for(int i = head[u] ; i ; i = E[i].next) {
int v = E[i].to;
if(v != fa) dfs(v,u);
}
}
void Main() {
dfs(1,0);
int64 res = fir;
for(int i = 2 ; i <= N ; ++i) {
res = max(res,fir + dis[0][i] - dis[1][i]);
}
ans[1] = all - res;
}
}
namespace two {
int64 dis[2][MAXN],fir,mval = 0;
pair<int64,int> dp[MAXN];
int siz[MAXN],dfn[MAXN],idx,line[MAXN],fa[MAXN],S = 1,T = 1;
bool vis[MAXN];
struct node {
int l,r,pos;int64 mv,lz;
}tr[MAXN * 4];
void dfs(int u) {
siz[u] = 1;dfn[u] = ++idx;line[idx] = u;
for(int i = head[u] ; i ; i = E[i].next) {
int v = E[i].to;
if(v == fa[u]) {dis[1][u] = dis[1][fa[u]] + E[i].val;fir += E[i].val;}
else dis[0][v] = dis[0][u] + E[i].val;
}
dp[u] = mp(0,u);
for(int i = head[u] ; i ; i = E[i].next) {
int v = E[i].to;
if(v != fa[u]) {
fa[v] = u;
dfs(v);
siz[u] += siz[v];
if(E[i].val + dp[v].fi + dp[u].fi - dis[1][u] + dis[0][u] > mval) {
mval = E[i].val + dp[v].fi + dp[u].fi - dis[1][u] + dis[0][u];
S = dp[u].se;T = dp[v].se;
}
if(dp[v].fi + E[i].val > dp[u].fi) {
dp[u].fi = dp[v].fi + E[i].val;dp[u].se = dp[v].se;
}
}
}
}
void update(int u) {
if(tr[u << 1].mv > tr[u << 1 | 1].mv) {
tr[u].mv = tr[u << 1].mv;
tr[u].pos = tr[u << 1].pos;
}
else {
tr[u].mv = tr[u << 1 | 1].mv;
tr[u].pos = tr[u << 1 | 1].pos;
}
}
void addlz(int u,int64 v) {
tr[u].mv += v;tr[u].lz += v;
}
void pushdown(int u) {
if(tr[u].lz) {
addlz(u << 1,tr[u].lz);
addlz(u << 1 | 1,tr[u].lz);
tr[u].lz = 0;
}
}
void build(int u,int l,int r) {
tr[u].l = l;tr[u].r = r;
if(l == r) {
tr[u].mv = dis[0][line[l]];tr[u].pos = line[l];
return;
}
int mid = (l + r) >> 1;
build(u << 1,l,mid);
build(u << 1 | 1,mid + 1,r);
update(u);
}
void Add(int u,int l,int r,int64 v) {
if(tr[u].l == l && tr[u].r == r) {addlz(u,v);return;}
pushdown(u);
int mid = (tr[u].l + tr[u].r) >> 1;
if(r <= mid) Add(u << 1,l,r,v);
else if(l > mid) Add(u << 1 | 1,l,r,v);
else {Add(u << 1,l,mid,v);Add(u << 1 | 1,mid + 1,r,v);}
update(u);
}
int64 Query(int u,int pos) {
if(tr[u].l == tr[u].r) return tr[u].mv;
pushdown(u);
int mid = (tr[u].l + tr[u].r) >> 1;
if(pos <= mid) return Query(u << 1,pos);
else return Query(u << 1 | 1,pos);
}
void Delete(int u) {
int pre = 0;
while(u && !vis[u]) {
int64 t = Query(1,dfn[u]);
if(!pre) Add(1,dfn[u],dfn[u] + siz[u] - 1,-t);
else {
Add(1,dfn[u],dfn[pre] - 1,-t);
if(dfn[pre] + siz[pre] <= dfn[u] + siz[u] - 1)
Add(1,dfn[pre] + siz[pre],dfn[u] + siz[u] - 1,-t);
}
vis[u] = 1;
pre = u;u = fa[u];
}
}
void More(int x) {
ans[x] = ans[x - 1] - tr[1].mv;
Delete(tr[1].pos);
}
void Main() {
dfs(1);
ans[2] = all - (fir + mval);
memset(dis,0,sizeof(dis));
fa[S] = 0;idx = 0;
dfs(S);
build(1,1,N);
Delete(T);
}
}
void Solve() {
read(N);
int a,b,c,d;
for(int i = 1 ; i < N ; ++i) {
read(a);read(b);read(c);read(d);
add(a,b,c);
add(b,a,d);
all += c;all += d;
}
one::Main();
if(N >= 2) two::Main();
for(int i = 3 ; i <= N ; ++i) {
two::More(i);
}
int Q;
read(Q);
for(int i = 1 ; i <= Q ; ++i) {
read(a);
out(ans[a]);enter;
}
}
int main() {
#ifdef ivorysi
freopen("f1.in","r",stdin);
#endif
Solve();
return 0;
}