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
#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;
}
# 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