Submission #1263682

#	Time	Username	Problem	Language	Result	Execution time	Memory
1263682		mingga	Two Antennas (JOI19_antennas)	C++20	0 / 100	167 ms	42956 KiB

antennas

// Author: caption_mingle
#include "bits/stdc++.h"

using namespace std;

#define ln "\n"
#define pb push_back
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define ll long long
const int mod = 1e9 + 7;
const ll inf = 2e18;
const int N = 2e5 + 7;
int n, q;
ll ans[N];

struct antennas {
	int h, a, b;
} d[N];

struct SEGTREE {
	struct node {
		ll mx, mn, val;
		node() {
			mx = -inf;
			mn = inf;
			val = -inf;
		}
		node(int x, int y, int z) {
			mx = x, mn = y, val = z;
		}
		node operator + (const node& o) {
			mx = max(mx, o.mx);
			mn = min(mn, o.mn);
			val = max(val, o.val);
			return node(mx, mn, val);
		}
	};
	vector<node> st;
	vector<pair<ll, ll>> lazy;
	SEGTREE(int n) {
		st.resize(n * 4 + 4, node());
		lazy.resize(n * 4 + 4, {-inf, inf});
	}
	void push(int i) {
		if(lazy[i].fi != -inf) {
			auto [mx, mn] = lazy[i];
			lazy[i] = {-inf, inf};
			lazy[i * 2].fi = max(mx, lazy[i * 2].fi);
			lazy[i * 2].se = min(mn, lazy[i * 2].se);
			lazy[i * 2 + 1].fi = max(mx, lazy[i * 2 + 1].fi);
			lazy[i * 2 + 1].se = min(mn, lazy[i * 2 + 1].se);
			st[i * 2].val = max({st[i * 2].val, st[i * 2].mx - mn, mx - st[i * 2].mn});
			st[i * 2 + 1].val = max({st[i * 2 + 1].val, st[i * 2 + 1].mx - mn, mx - st[i * 2 + 1].mn});
		}
	}
	void update(int i, int l, int r, int u, ll x) {
		if(l > u or r < u) return ;
		if(l == r) {
			if(x == inf) st[i].mx = -inf, st[i].mn = inf;
			else st[i].mx = st[i].mn = x;
			return;
		}
		int m = (l + r) >> 1;
		update(i * 2, l, m, u, x);
		update(i * 2 + 1, m + 1, r, u, x);
		st[i] = st[i * 2] + st[i * 2 + 1];
	}
	void update(int i, int l, int r, int u, int v, ll x) {
		if(l > v or r < u) return ;
		if(u <= l and r <= v) {
			lazy[i].fi = max(lazy[i].fi, x);
			lazy[i].se = min(lazy[i].se, x);
			st[i].val = max({st[i].val, st[i].mx - x, x - st[i].mn});
			return;
		}
		int m = (l + r) >> 1;
		push(i);
		update(i * 2, l, m, u, v, x);
		update(i * 2 + 1, m + 1, r, u, v, x);
		st[i] = st[i * 2] + st[i * 2 + 1];
	}
	node get(int i, int l, int r, int u, int v) {
		if(l > v or r < u) return node();
		if(u <= l and r <= v) {
			return st[i];
		}
		int m = (l + r) >> 1;
		push(i);
		return get(i * 2, l, m, u, v) + get(i * 2 + 1, m + 1, r, u, v);
	}
	void update(int u, ll x) {
		update(1, 1, n, u, x);
	}
	void update(int l, int r, ll x) {
		update(1, 1, n, l, r, x);
	}
	ll get(int l, int r) {
		return get(1, 1, n, l, r).val;
	}
};

vector<pair<int, int>> ev[N], que[N];


signed main() {
	cin.tie(0) -> sync_with_stdio(0);
	#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++) {
		int h, a, b; cin >> h >> a >> b;
		d[i] = {h, a, b};
		if(i + a <= n) ev[i + a].pb({i, 1});
		if(i + b + 1 <= n) ev[i + b + 1].pb({i, -1});
	}
	cin >> q;
	for(int i = 1; i <= q; i++) {
		int l, r; cin >> l >> r;
		que[r].pb({l, i});
	}
	SEGTREE st(n);
	for(int i = 1; i <= n; i++) {
		for(auto [x, sign] : ev[i]) {
			if(sign == 1) st.update(x, d[x].h);
			else if(sign == -1) st.update(x, inf);
		}
		if(i - d[i].a >= 1) {
			st.update(max(1, i - d[i].b), i - d[i].a, d[i].h);
		}
		for(auto [l, id] : que[i]) {
			ans[id] = st.get(l, i);
			if(ans[id] < 0) ans[id] = -1;
		}
	}
	for(int i = 1; i <= q; i++) cout << ans[i] << ln;
    cerr << "\nTime: " << clock() * 1000 / CLOCKS_PER_SEC;
}

Compilation message (stderr)

antennas.cpp: In function 'int main()':
antennas.cpp:112:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  112 |                 freopen(task ".INP", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
antennas.cpp:113:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  113 |                 freopen(task ".OUT", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 2
• Subtask 2: 0 / 11
• Subtask 3: 0 / 22
• Subtask 4: 0 / 65