Submission #55226

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
55226	2018-07-06T12:40:24 Z	linkret	Sailing Race (CEOI12_race)	C++14	100 / 100	1387 ms	7212 KB

race

#include <bits/stdc++.h>

using namespace std;

const int maxn = 505, inf = 1e9;

int n, id;
vector<int> adj[maxn];
vector<int> radj[maxn];

bool between(int l, int r, int i) {
	if(l > r) {
		return i >= l || i <= r;
	} else {
		return i >= l && i <= r;
	}
}

int dist(int i, int j) {
	if(i <= j)
		return j - i;
	return n - i + j;
}

int dp[2][2][maxn][maxn];
int f[2][maxn][maxn];

int main() {
	ios_base::sync_with_stdio(false);

	cin >> n >> id;

	for(int i = 0, j; i < n; i++) {
		while(true) {
			cin >> j;
			if(!j) break;
			j--;
			adj[i].push_back(j);
			radj[j].push_back(i);
		}
	}

	for(int i = 0; i < n; i++) {
		for(int j = 0; j < n; j++) {
			f[0][i][j] = -1;
			f[1][i][j] = -1;

			for(int k : radj[i]) {
				if(between(j, i, k))
					continue;

				if(f[0][i][j] == -1)
					f[0][i][j] = k;

				if(dist(i, f[0][i][j]) < dist(i, k))
					f[0][i][j] = k;
			}

			for(int k : radj[i]) {
				if(between(i, j, k))
					continue;

				if(f[1][i][j] == -1)
					f[1][i][j] = k;

				if(dist(i, f[1][i][j]) > dist(i, k))
					f[1][i][j] = k;
			}
		}
	}

	for(int i = 0; i < n; i++) {
		for(int j = 0; j < n; j++) {
			dp[1][0][i][j] = -inf;
			dp[1][1][i][j] = -inf;
		}
	}

	for(int i = 0; i < n; i++) {
		dp[1][0][i][i] = 0;
		dp[1][1][i][i] = 0;
	}

	for(int len = 1; len < n; len++) {
		for(int i = 0; i < n; i++) {
			int j = (i + len) % n;
			
			for(int k : radj[j]) {
				if(between(i, j, k)) {
					dp[1][0][i][j] = max(dp[1][0][i][j], 1 + dp[1][0][i][k]);
				}
			}

			for(int k : radj[i]) {
				if(between(i, j, k)) {
					dp[1][1][i][j] = max(dp[1][1][i][j], 1 + dp[1][1][k][j]);
				}
			}

			for(int k : adj[i]) {
				if(between(i, j, k)) {
					dp[0][0][i][j] = max(dp[0][0][i][j], 1 + max(dp[0][1][(i + 1) % n][k], dp[0][0][k][j]));
				}
			}

			for(int k : adj[j]) {
				if(between(i, j, k)) {
					dp[0][1][i][j] = max(dp[0][1][i][j], 1 + max(dp[0][1][i][k], dp[0][0][k][(j - 1 + n) % n]));
				}
			}
		}
	}

	int mxm = 0, t = 0;

	for(int i = 0; i < n; i++) {
		int tmp = dp[0][0][i][(i - 1 + n) % n];
		if(tmp > mxm) {
			mxm = tmp;
			t = i;
		}
	}

	if(id) {
		for(int i = 0; i < n; i++) {
			for(int j = 0, l; j < n; j++) {
				if(i == j)
					continue;

				for(int k : adj[j]) {
					if(i == k || j == k)
						continue;

					if(between(j, k, i)) 
						l = f[0][i][j];
					else
						l = f[1][i][j];

					if(l == i || l == j || l == k || l == -1)
						continue;

					if(between(j, k, i)) {
						int tmp = 0;

						if(between(k, j, l)) {
							tmp = dp[1][1][j][i] + 2 + max(dp[0][1][(i + 1) % n][k], dp[0][0][k][l]);
						}
					
						if(tmp > mxm) {
							mxm = tmp;
							t = l;
						}
					} else {
						int tmp = 0;

						if(between(j, k, l)) {
							tmp = dp[1][0][i][j] + 2 + max(dp[0][0][k][(i - 1 + n) % n], dp[0][1][l][k]);
						}
						
						if(tmp > mxm) {
							mxm = tmp;
							t = l;
						}
					}
				}
			}
		}
	}

	cout << mxm << endl << t + 1 << endl;

	// for(int i = 0; i < n; i++) {
	// 	for(int j = 0; j < n; j++) {
	// 		int k = dp[0][1][i][j];
	// 		if(k < 0)
	// 			cout << 'x' << " ";
	// 		else
	// 			cout << k << " ";
	// 	}
	// 	cout << endl;
	// }

	// for(int i = 0; i < n; i++) {
	// 	for(int j = 0; j < n; j++) {
	// 		cout << f[i][j] << " ";
	// 	}
	// 	cout << endl;
	// }

	return 0;
}

Subtask #1

100.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	3 ms	504 KB	Output is correct
2	Correct	3 ms	812 KB	Output is correct
3	Correct	3 ms	812 KB	Output is correct
4	Correct	5 ms	956 KB	Output is correct
5	Correct	5 ms	1056 KB	Output is correct
6	Correct	5 ms	1148 KB	Output is correct
7	Correct	10 ms	1256 KB	Output is correct
8	Correct	9 ms	1464 KB	Output is correct
9	Correct	13 ms	1624 KB	Output is correct
10	Correct	30 ms	1752 KB	Output is correct
11	Correct	17 ms	1752 KB	Output is correct
12	Correct	69 ms	3068 KB	Output is correct
13	Correct	151 ms	4212 KB	Output is correct
14	Correct	175 ms	5376 KB	Output is correct
15	Correct	687 ms	6912 KB	Output is correct
16	Correct	875 ms	7088 KB	Output is correct
17	Correct	821 ms	7088 KB	Output is correct
18	Correct	230 ms	7088 KB	Output is correct
19	Correct	1063 ms	7088 KB	Output is correct
20	Correct	1387 ms	7212 KB	Output is correct