/*************************************
* author: marvinthang *
* created: 11.03.2024 18:56:24 *
*************************************/
#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define left ___left
#define right ___right
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
#define MASK(i) (1LL << (i))
#define BIT(x, i) ((x) >> (i) & 1)
#define __builtin_popcount __builtin_popcountll
#define ALL(v) (v).begin(), (v).end()
#define REP(i, n) for (int i = 0, _n = (n); i < _n; ++i)
#define REPD(i, n) for (int i = (n); i-- > 0; )
#define FOR(i, a, b) for (int i = (a), _b = (b); i < _b; ++i)
#define FORD(i, b, a) for (int i = (b), _a = (a); --i >= _a; )
#define FORE(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORDE(i, b, a) for (int i = (b), _a = (a); i >= _a; --i)
#define scan_op(...) istream & operator >> (istream &in, __VA_ARGS__ &u)
#define print_op(...) ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#ifdef LOCAL
#include "debug.h"
#else
#define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
#define DB(...) 23
#define db(...) 23
#define debug(...) 23
#endif
template <class U, class V> scan_op(pair <U, V>) { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>) { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>) { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream & print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")"; else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class ...U> print_op(tuple<U...>) { return print_tuple_utils<0, tuple<U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))> typename enable_if <!is_same<Con, string>::value, ostream&>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }
template <class A, class B> bool minimize(A &a, B b) { return a > b ? a = b, true : false; }
template <class A, class B> bool maximize(A &a, B b) { return a < b ? a = b, true : false; }
// end of template
const int MOD = 1e9 + 7;
void process(void) {
int n; cin >> n;
vector <int> par(n);
vector <long long> lengths(n);
vector <vector <int>> adj(n);
FOR(i, 1, n) {
cin >> par[i];
adj[par[i]].push_back(i);
}
FOR(i, 1, n) cin >> lengths[i];
vector <int> tin(n), tout(n), depth(n), val(n), pos(n);
long long res = 0;
function<pair <long long, int>(int)> dfs = [&] (int u) {
static int t = 0;
val[t] = u;
tin[u] = t++;
pair <long long, int> cur(lengths[u], u);
long long se = lengths[u];
for (int v: adj[u]) {
lengths[v] += lengths[u];
depth[v] = depth[u] + 1;
pair <long long, int> val = dfs(v);
if (cur < val) {
se = cur.fi;
cur = val;
} else maximize(se, val.fi);
}
res += cur.fi + se - 2 * lengths[u];
tout[u] = t;
pos[cur.se] = u;
return cur;
};
dfs(0);
vector <pair <long long, int>> st(n + n);
vector <long long> lazy(n);
int h = __lg(n + n - 1);
REP(i, n) st[i + n] = pair{lengths[val[i]], val[i]};
FORD(i, n, 1) st[i] = max(st[i << 1], st[i << 1 | 1]);
auto apply = [&] (int i, long long val) {
st[i].fi += val;
if (i < n) lazy[i] += val;
};
auto pushUp = [&] (int i) {
while (i >>= 1) {
st[i] = max(st[i << 1], st[i << 1 | 1]);
st[i].fi += lazy[i];
}
};
auto pushDown = [&] (int p) {
FORD(s, h, 1) {
int i = p >> s;
if (lazy[i]) {
apply(i << 1, lazy[i]);
apply(i << 1 | 1, lazy[i]);
lazy[i] = 0;
}
}
};
auto update = [&] (int l0, int r0, int val) {
l0 += n; r0 += n;
for (int l = l0, r = r0; l < r; l >>= 1, r >>= 1) {
if (l & 1) apply(l++, val);
if (r & 1) apply(--r, val);
}
pushUp(l0); pushUp(r0 - 1);
};
auto getMax = [&] (int l, int r) {
l += n; r += n;
pushDown(l); pushDown(r - 1);
pair <long long, int> res(0, -1);
for (; l < r; l >>= 1, r >>= 1) {
if (l & 1) maximize(res, st[l++]);
if (r & 1) maximize(res, st[--r]);
}
return res;
};
int q; cin >> q;
res %= MOD;
cout << res << '\n';
while (q--) {
int u, add; cin >> u >> add;
pair <long long, int> cur = getMax(tin[u], tout[u]);
cur.fi += add;
int p = pos[cur.se];
res += 1LL * (depth[u] - depth[p]) * add;
while (p) {
pair <long long, int> fip = getMax(tin[par[p]], tout[par[p]]);
int child = *prev(partition_point(ALL(adj[par[p]]), [&] (int x) { return tin[x] <= tin[fip.se]; }));
pair <long long, int> sep = max(getMax(tin[par[p]], tin[child]), getMax(tout[child], tout[par[p]]));
if (cur > fip) {
int w = pos[fip.se];
res += 1LL * (depth[p] - depth[w]) * (cur.fi - fip.fi) + fip.fi - sep.fi;
pos[fip.se] = child;
p = w;
} else {
if (cur > sep) res += cur.fi - sep.fi;
break;
}
}
pos[cur.se] = p;
update(tin[u], tout[u], add);
res %= MOD;
if (res < 0) res += MOD;
cout << res << '\n';
}
}
int main(void) {
ios_base::sync_with_stdio(false); cin.tie(nullptr); // cout.tie(nullptr);
file("arboras");
// int t; cin >> t; while (t--)
process();
// cerr << "Time elapsed: " << TIME << " s.\n";
return (0^0);
}
Compilation message
arboras.cpp: In function 'int main()':
arboras.cpp:30:61: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
30 | #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
arboras.cpp:158:2: note: in expansion of macro 'file'
158 | file("arboras");
| ^~~~
arboras.cpp:30:94: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
30 | #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
arboras.cpp:158:2: note: in expansion of macro 'file'
158 | file("arboras");
| ^~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
600 KB |
Output is correct |
| 2 |
Correct |
1 ms |
604 KB |
Output is correct |
| 3 |
Correct |
1 ms |
348 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
122 ms |
12300 KB |
Output is correct |
| 2 |
Correct |
81 ms |
11212 KB |
Output is correct |
| 3 |
Correct |
81 ms |
11312 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
103 ms |
14672 KB |
Output is correct |
| 2 |
Correct |
87 ms |
20388 KB |
Output is correct |
| 3 |
Correct |
108 ms |
14928 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
600 KB |
Output is correct |
| 2 |
Correct |
1 ms |
604 KB |
Output is correct |
| 3 |
Correct |
1 ms |
348 KB |
Output is correct |
| 4 |
Correct |
122 ms |
12300 KB |
Output is correct |
| 5 |
Correct |
81 ms |
11212 KB |
Output is correct |
| 6 |
Correct |
81 ms |
11312 KB |
Output is correct |
| 7 |
Correct |
103 ms |
14672 KB |
Output is correct |
| 8 |
Correct |
87 ms |
20388 KB |
Output is correct |
| 9 |
Correct |
108 ms |
14928 KB |
Output is correct |
| 10 |
Correct |
137 ms |
16720 KB |
Output is correct |
| 11 |
Correct |
88 ms |
20180 KB |
Output is correct |
| 12 |
Correct |
93 ms |
14544 KB |
Output is correct |
| 13 |
Correct |
75 ms |
19844 KB |
Output is correct |
| 14 |
Correct |
70 ms |
20944 KB |
Output is correct |
