#include "catdog.h"
#include <vector>
#include <algorithm>
using namespace std;
const int MX = 100005;
const int inf = 1000000069;
int n, a[MX], b[MX];
vector<int> adj[MX];
int sz[MX], depth[MX], head[MX], in[MX], cnt[MX], par[MX], tim = 0;
void dfs_sz(int nw){
sz[nw] = 1;
for(int &nx : adj[nw]){
par[nx] = nw;
depth[nx] = depth[nw] + 1;
adj[nx].erase(find(adj[nx].begin(), adj[nx].end(), nw));
dfs_sz(nx);
sz[nw] += sz[nx];
if(sz[nx] > sz[adj[nw][0]])
swap(nx, adj[nw][0]);
}
}
void dfs_hld(int nw){
in[nw] = tim ++;
cnt[head[nw]] ++;
for(int nx : adj[nw]){
head[nx] = (nx == adj[nw][0] ? head[nw] : nx);
dfs_hld(nx);
}
}
void init_hld(int root = 0){
par[root] = depth[root] = tim = 0;
dfs_sz(root);
head[root] = root;
dfs_hld(root);
}
struct dat{
int dp[2][2];
dat(){dp[0][0] = dp[0][1] = dp[1][0] = dp[1][1] = inf;}
dat(int s0, int s1, int tp){
dp[0][0] = dp[0][1] = dp[1][0] = dp[1][1] = inf;
if(tp != 2) dp[0][0] = s0;
if(tp != 1) dp[1][1] = s1;
}
};
dat merge(dat lf, dat rg){
dat rs = dat();
for(int pl = 0; pl < 2; pl ++)
for(int ql = 0; ql < 2; ql ++) if(lf.dp[pl][ql] != inf){
for(int pr = 0; pr < 2; pr ++)
for(int qr = 0; qr < 2; qr ++) if(rg.dp[pr][qr] != inf){
rs.dp[pl][qr] = min(rs.dp[pl][qr],
lf.dp[pl][ql] + (ql ^ pr) + rg.dp[pr][qr]);
}
}
return rs;
}
dat st[MX * 4];
void build_tree(int nd, int cl, int cr){
if(cl == cr) return void(st[nd] = dat(0, 0, 0));
build_tree(nd * 2, cl, (cl + cr) / 2);
build_tree(nd * 2 + 1, (cl + cr) / 2 + 1, cr);
st[nd] = merge(st[nd * 2], st[nd * 2 + 1]);
}
void upd_tree(int nd, int cl, int cr, int ps, int s0, int s1, int tp){
if(ps < cl || cr < ps) return;
if(cl == cr) return void(st[nd] = dat(s0, s1, tp));
upd_tree(nd * 2, cl, (cl + cr) / 2, ps, s0, s1, tp);
upd_tree(nd * 2 + 1, (cl + cr) / 2 + 1, cr, ps, s0, s1, tp);
st[nd] = merge(st[nd * 2], st[nd * 2 + 1]);
}
dat que_tree(int nd, int cl, int cr, int lf, int rg){
if(lf <= cl && cr <= rg) return st[nd];
if(rg <= (cl + cr) / 2)
return que_tree(nd * 2, cl, (cl + cr) / 2, lf, rg);
if((cl + cr) / 2 < lf)
return que_tree(nd * 2 + 1, (cl + cr) / 2 + 1, cr, lf, rg);
return merge(
que_tree(nd * 2, cl, (cl + cr) / 2, lf, rg),
que_tree(nd * 2 + 1, (cl + cr) / 2 + 1, cr, lf, rg)
);
}
int tp[MX], s0[MX], s1[MX];
dat get_dp(int x){
return que_tree(1, 0, n - 1, in[x], in[head[x]] + cnt[head[x]] - 1);
}
void upd_ac(int x){
upd_tree(1, 0, n - 1, in[x], s0[x], s1[x], tp[x]);
}
int get_ans(){
dat r1 = get_dp(0);
int ans = inf;
for(int i = 0; i < 2; i ++)
for(int j = 0; j < 2; j ++)
ans = min(ans, r1.dp[i][j]);
return ans;
}
void change_type(int nw, int t){
for(int cr = nw; head[cr]; cr = par[head[cr]]){
dat cur = get_dp(cr);
int dp0 = min(cur.dp[0][0], cur.dp[0][1]);
int dp1 = min(cur.dp[1][0], cur.dp[1][1]);
s0[par[cr]] -= min(dp0, dp1 + 1);
s1[par[cr]] -= min(dp1, dp0 + 1);
}
tp[nw] = t;
upd_ac(nw);
for(int cr = nw; head[cr]; cr = par[head[cr]]){
dat cur = get_dp(cr);
int dp0 = min(cur.dp[0][0], cur.dp[0][1]);
int dp1 = min(cur.dp[1][0], cur.dp[1][1]);
s0[par[cr]] += min(dp0, dp1 + 1);
s1[par[cr]] += min(dp1, dp0 + 1);
upd_ac(par[cr]);
}
}
void init(){
for(int i = 0; i < n - 1; i ++){
adj[a[i]].push_back(b[i]);
adj[b[i]].push_back(a[i]);
}
init_hld();
build_tree(1, 0, n - 1);
}
void initialize(int _n, vector<int> _a, vector<int> _b){
n = _n;
for(int i = 0; i < n - 1; i ++)
a[i] = _a[i] - 1, b[i] = _b[i] - 1;
init();
}
int cat(int v){
change_type(v - 1, 1);
return get_ans();
}
int dog(int v){
change_type(v - 1, 2);
return get_ans();
}
int neighbor(int v){
change_type(v - 1, 0);
return get_ans();
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
6 ms |
8908 KB |
Output is correct |
| 2 |
Incorrect |
6 ms |
8908 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
6 ms |
8908 KB |
Output is correct |
| 2 |
Incorrect |
6 ms |
8908 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
6 ms |
8908 KB |
Output is correct |
| 2 |
Incorrect |
6 ms |
8908 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
