Submission #245054

#	Time	Username	Problem	Language	Result	Execution time	Memory
245054		vioalbert	Collecting Stamps 3 (JOI20_ho_t3)	C++14	25 / 100	2091 ms	114948 KiB

ho_t3

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const ll N = 205;
ll n, l;
ll cl[N], ccl[N], t[N];

void read() {
	cin >> n >> l;
	for(int i = 1; i <= n; i++) {
		cin >> cl[i];
		ccl[i] = l - cl[i];
	}
	for(int i = 1; i <= n; i++)
		cin >> t[i];
}

struct state {
	int l, r, cnt, dir;
	state(int _l, int _r, int _cnt, int _dir) : l(_l), r(_r), cnt(_cnt), dir(_dir) {}
	bool operator<(const state& ot) const {
		return cnt < ot.cnt;
	}
};

void solve() {
	priority_queue<pair<ll, state>, vector<pair<ll, state>>, greater<pair<ll, state>>> pq;
	ll dist[n+2][n+2][n+2][2];
	for(int i = 1; i <= n+1; i++) {
		for(int j = i-1; j <= n; j++) {
			for(int k = 0; k <= n; k++)
				dist[i][j][k][0] = dist[i][j][k][1] = -1;
		}
	}
	ll cost, total;
	int ans = 0;
	pq.emplace(0, state(1, n, 0, 0));
	dist[1][n][0][0] = 0;
	while(!pq.empty()) {
		ll d = pq.top().first; state u = pq.top().second; pq.pop();
		if(dist[u.l][u.r][u.cnt][u.dir] == d) {
			if(u.l > u.r) {
				ans = max(ans, u.cnt);
				continue;
			}

			if(u.dir == 0) {
				cost = ((u.l==1)?0:-cl[u.l-1]) + cl[u.l];
				total = d + cost;
				ll& nxt1 = dist[u.l+1][u.r][u.cnt + (total <= t[u.l])][0];
				if(nxt1 == -1 || nxt1 > total) {
					nxt1 = total;
					pq.emplace(nxt1, state(u.l+1, u.r, u.cnt + (total <= t[u.l]), 0));
				}

				cost = ((u.l==1)?0:cl[u.l-1]) + ccl[u.r];
				total = d + cost;
				ll& nxt2 = dist[u.l][u.r-1][u.cnt + (total <= t[u.r])][1];
				if(nxt2 == -1 || nxt2 > total) {
					nxt2 = total;
					pq.emplace(nxt2, state(u.l, u.r-1, u.cnt + (total <= t[u.r]), 1));
				}
			} else {
				cost = ((u.r==n)?0:-ccl[u.r+1]) + ccl[u.r];
				total = d + cost;
				ll& nxt1 = dist[u.l][u.r-1][u.cnt + (total <= t[u.r])][1];
				if(nxt1 == -1 || nxt1 > total) {
					nxt1 = total;
					pq.emplace(nxt1, state(u.l, u.r-1, u.cnt + (total <= t[u.r]), 1));
				}

				cost = ((u.r==n)?0:ccl[u.r+1]) + cl[u.l];
				total = d + cost;
				ll& nxt2 = dist[u.l+1][u.r][u.cnt + (total <= t[u.l])][0];
				if(nxt2 == -1 || nxt2 > total) {
					nxt2 = total;
					pq.emplace(nxt2, state(u.l+1, u.r, u.cnt + (total <= t[u.l]), 0));
				}
			}
		}
	}
	cout << ans << '\n';
}

int main() {
	ios::sync_with_stdio(0); cin.tie(0);
	read();
	solve();
	return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 0 / 75