#include<bits/stdc++.h>
#define fori(i,a,b) for(int i=a;i<=b;i++)
#define int long long
#define pb push_back
using namespace std;
typedef pair<int,int> ii;
typedef tuple<int,int,int> tp;
const int M=1e6+10;
const int N=1e3+10;
const int mod=1e9+7;
int n,p[M];
vector<int> ke[M];
int num[M],tail[M],cnt = 0,up[M][20],d[M];
int arr[M];
void dfs(int u,int p)
{
num[u] = ++ cnt;
arr[cnt] = u;
for(int i = 1;i <= 18; i++) up[u][i] = up[up[u][i - 1]][i - 1];
for(int v : ke[u]) {
if(v == p) continue;
d[v] = d[u] + 1;
up[v][0] = u;
dfs(v,u);
}
tail[u] = cnt;
}
bool anc(int u ,int v)
{
return num[u] <= num[v] && tail[u] >= tail[v];
}
int lca(int u,int v)
{
if(anc(u,v)) return u;
if(anc(v,u)) return v;
for(int i = 18;i >= 0;i--) if(!anc(up[u][i],v)) u = up[u][i];
return up[u][0];
}
int dist(int u,int v)
{
int x = lca(u,v);
return d[u] + d[v] - 2 * d[x];
}
ii t[4 * M];
int lz[4 * M];
void lazy(int s)
{
t[s * 2].first += lz[s];
t[s * 2 + 1].first += lz[s];
lz[s * 2] += lz[s];
lz[s * 2 + 1] += lz[s];
lz[s] = 0;
return ;
}
void build(int s,int l,int r)
{
if(l == r) {
t[s] = {p[arr[l]],arr[l]};
return ;
}
int mid = (l + r)/2;
build(s * 2,l,mid);
build(s * 2 + 1,mid + 1,r);
t[s] = max(t[s * 2], t[s * 2 + 1]);
}
void upd(int s,int l,int r,int u,int v,int val)
{
if(v < l || r < u) return ;
if(u <= l && r <= v) {
t[s].first += val;
lz[s] += val;
return ;
}
int mid = (l + r)/2;
if(l != r && lz[s]) lazy(s);
upd(s * 2,l,mid,u,v,val);
upd(s * 2 + 1,mid + 1,r,u,v,val);
t[s] = max(t[s * 2],t[s * 2 + 1]);
}
int pos[M],f[M];
int solve(int u)
{
upd(1,1,n,num[u],tail[u],-1e9);
int nxt = t[1].second;
// cout << u << ' ' << t[1].first << " " << t[1].second << "\n";
if(t[1].first > 0) {
solve(nxt);
f[u] = max(f[u],f[nxt] + dist(u,nxt));
}
upd(1,1,n,num[u],tail[u],1e9);
upd(1,1,n,1,n,-1e9);
for(int v : ke[u]) {
if(v == up[u][0]) continue;
upd(1,1,n,num[v],tail[v],1e9);
nxt = t[1].second;
if(t[1].first > 0) {
solve(nxt);
f[u] = max(f[u],f[nxt] + dist(u,nxt));
}
upd(1,1,n,num[v],tail[v],-1e9);
}
upd(1,1,n,1,n,1e9);
}
int32_t main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
if(fopen("1.inp","r"))
{
freopen("1.inp","r",stdin);
freopen("1.out","w",stdout);
}
#define task ""
if(fopen(task".inp","r"))
{
freopen(task".inp","r",stdin);
freopen(task".out","w",stdout);
}
cin >> n ;
for(int i =1;i <= n; i++) cin >> p[i];
for(int i =1;i <= n - 1; i++) {
int u,v;
cin >> u >> v;
ke[u].pb(v);
ke[v].pb(u);
}
up[1][0] = 1;
dfs(1,0);
build(1,1,n);
int x = t[1].second;
solve(x);
cout << f[x];
}
Compilation message
Main.cpp: In function 'long long int solve(long long int)':
Main.cpp:116:1: warning: no return statement in function returning non-void [-Wreturn-type]
116 | }
| ^
Main.cpp: In function 'int32_t main()':
Main.cpp:125:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
125 | freopen("1.inp","r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~
Main.cpp:126:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
126 | freopen("1.out","w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~
Main.cpp:131:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
131 | freopen(task".inp","r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:132:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
132 | freopen(task".out","w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Execution timed out |
2009 ms |
1048576 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Execution timed out |
2009 ms |
1048576 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Execution timed out |
2009 ms |
1048576 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Execution timed out |
2009 ms |
1048576 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Execution timed out |
2009 ms |
1048576 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1737 ms |
1048576 KB |
Execution killed with signal 9 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Execution timed out |
2009 ms |
1048576 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |