Submission #680364

#	Time	Username	Problem	Language	Result	Execution time	Memory
680364		vjudge1	Sailing Race (CEOI12_race)	C++17	40 / 100	142 ms	2648 KiB

race

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 503;

int n, k, dp_before[MAXN][MAXN][2], dp_after[MAXN][MAXN][2];
int ans, ans_node;
vector<int> adj[MAXN];

inline bool include(int i, int j, int k){
	if(i < k) return (i <= j && j <= k);
	return (i <= j || j <= k);
}
inline int nxt(int i){
	return ((i == n - 1) ? 0 : i + 1);
}
inline int prv(int i){
	return ((i == 0) ? n - 1 : i - 1);
}

int main(){
	cin >> n >> k;
	for(int i = 0; i < n; ++i){
		int x; cin >> x;
		while(x){
			--x;
			adj[i].push_back(x);
			cin >> x;
		}
	}
	
	for(int off = 1; off < n; ++off){
		for(int i = 0; i < n; ++i){
			int j = (i + off) % n;
			for(int x : adj[i]){
				if(include(i, x, j)){
					dp_after[i][j][0] = max(dp_after[i][j][0], max(dp_after[x][j][0], dp_after[nxt(i)][x][1]) + 1);
				}
			}
			for(int x : adj[j]){
				if(include(i, x, j)){
					dp_after[i][j][1] = max(dp_after[i][j][1], max(dp_after[x][prv(j)][0], dp_after[i][x][1]) + 1);
				}
			}
			if(dp_after[i][j][0] > ans){
				ans = dp_after[i][j][0];
				ans_node = i;
			}
			if(dp_after[i][j][1] > ans){
				ans = dp_after[i][j][1];
				ans_node = j;
			}
		}
	}
	cout << ans << " " << ans_node + 1;
	return 0;
}

• Subtask 1: 40 / 100