Submission #943430

#	Time	Username	Problem	Language	Result	Execution time	Memory
943430		vjudge1	Arboras (RMI20_arboras)	C++17	100 / 100	122 ms	19284 KiB

arboras

/*************************************
*    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 (stderr)

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");
      |  ^~~~

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 31 / 31
• Subtask 4: 45 / 45