Submission #345102

#	Time	Username	Problem	Language	Result	Execution time	Memory
345102		Kevin_Zhang_TW	Tropical Garden (IOI11_garden)	C++17	0 / 100	6 ms	7532 KiB

garden

#pragma GCC optimize("Ofast")
#pragma GCC target("avx2", "sse4")
#include "garden.h"
#include "gardenlib.h"

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pb emplace_back
#define AI(i) begin(i), end(i)
template<class T> bool chmin(T &a, T b) { return b < a ? (a = b, true) : false; }
template<class T> bool chmax(T &a, T b) { return a < b ? (a = b, true) : false; }
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() { cerr << endl; }
template<class T, class ...U> void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
template<class T> void debug(T L, T R) { while (L != R) cerr << *L << " \n"[next(L) == R], ++L; }
#else
#define DE(...) 0
#define debug(...) 0
#endif
const int MAX_N = 300010, MAX_K = 30, inf = 1e9 + 7;

int nxt[MAX_K][MAX_N], n;
int cur[MAX_N], dp[2][MAX_N], ring[2];
vector<int> rev[MAX_N];
void count_routes(int N, int M, int P, int R[][2], int Q, int G[]) {
	{
		auto nxt0 = nxt[0];
		fill(nxt0, nxt0 + N * 2, -1);
		vector<vector<int>> edge(N);
		for (int i = 0;i < M;++i) {
			int a = R[i][0], b = R[i][1];
			edge[a].pb(b), edge[b].pb(a);
		}
		for (int i = 0;i < N;++i) {
			nxt0[i] = edge[i][0];
			if (i == edge[ nxt0[i] ][0]) nxt0[i] += N;
			nxt0[i + N] = nxt0[i];
			if (edge[i].size() > 1) {
				nxt0[i + N] = edge[i][1];
				if (i == edge[ nxt0[i + N] ][0]) nxt0[i + N] += N;
			}
		}
		for (int i = 0;i < N+N;++i)
			rev[ nxt0[i] ].pb(i);
	}
	auto update = [&](int s, int* dp, int &ringlen) {
		ringlen = inf;
		fill(dp, dp + N + N, inf); dp[s] = 0;
		queue<int> q;
		q.emplace(s);
		while (q.size()) {
			int x = q.front(); q.pop();
			for (int u : rev[x]) if (chmin(dp[u], dp[x] + 1))
				q.emplace(u);
			for (int u : rev[x]) if (u == s)
				chmin(ringlen, dp[x]);
		}

	};
	update(P, dp[0], ring[0]), update(P+N, dp[1], ring[1]);

	for (int i = 0;i < Q;++i) {
		int res = 0, K = G[i];
		auto valid = [&](int s, int to) {
			return K >= dp[to][s] && (K - dp[to][s]) % ring[to] == 0;
		};
		for (int j = 0;j < N;++j) {
			if (valid(j, 0) || valid(j, 1))
				++res;
		}
		answer(res);
	}
}

• Subtask 1: 0 / 49
• Subtask 2: 0 / 20
• Subtask 3: 0 / 31