#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#define int long long
using namespace std;
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
vector<int> a(n);
for(int i = 0; i < n; ++i){
cin >> a[i];
}
vector<vector<int>> way(n);
for(int i = 1; i < n; ++i){
int x;
cin >> x;
--x;
way[x].push_back(i);
way[i].push_back(x);
}
int ans = 0;
auto sol = [&](int rt){
int allsum = 0, cnt = 0;
auto dfs = [&](auto&&self, int x, int pr, int psum)->void{
allsum += a[x] * psum;
cnt += a[x];
for(auto&nxt:way[x]){
if(nxt == pr){
continue;
}
self(self, nxt, x, psum + a[x]);
}
};
vector<int> vc;
for(int i = 0; i < (int)way[rt].size(); ++i){
cnt = 0;
dfs(dfs, way[rt][i], rt, a[rt]);
vc.push_back(cnt);
}
bitset<360004> dp;
dp[0] = 1;
for(auto&i:vc){
dp |= (dp << i);
}
int mx = 0;
int szsum = accumulate(vc.begin(), vc.end(), 0ll);
for(int i = 0; i < (int)dp.size(); ++i){
if(dp[i]){
mx = max(mx, i * (szsum - i));
}
}
ans = allsum + mx;
};
vector<int> sz(n);
auto dfssz = [&](auto&&self, int x, int pr)->void{
sz[x] = a[x];
for(auto&nxt:way[x]){
if(nxt == pr){
continue;
}
self(self, nxt, x);
sz[x] += sz[nxt];
}
};
dfssz(dfssz, 0, -1);
auto getcent = [&](auto&&self, int x, int pr)->int{
for(auto&nxt:way[x]){
if(nxt == pr){
continue;
}
if(sz[nxt] * 2 > sz[0]){
return self(self, nxt, x);
}
}
return x;
};
int ct = getcent(getcent, 0, -1);
// sol(ct);
for(int i = 0; i < n; ++i){
sol(i);
}
for(int i = 0; i < n; ++i){
ans += a[i] * (a[i] - 1);
}
cout << ans << '\n';
return 0;
}
Compilation message
Main.cpp: In function 'int main()':
Main.cpp:93:6: warning: unused variable 'ct' [-Wunused-variable]
93 | int ct = getcent(getcent, 0, -1);
| ^~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
202 ms |
488 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
202 ms |
488 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
10 ms |
448 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |