Submission #36759

#	Time	Username	Problem	Language	Result	Execution time	Memory
36759		RockyB	Sailing Race (CEOI12_race)	C++14	75 / 100	3000 ms	6568 KiB

race

/// In The Name Of God

#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,sse3,sse4,popcnt,abm,mmx")

#include <bits/stdc++.h>

#define f first
#define s second

#define pb push_back
#define pp pop_back
#define mp make_pair

#define sz(x) (int)x.size()
#define sqr(x) ((x) * 1ll * (x))
#define all(x) x.begin(), x.end()

#define Kazakhstan ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);

#define nl '\n'
#define ioi exit(0);

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;

const int N = (int)500 + 7, inf = (int)1e9 + 7, mod = (int)1e9 + 7;
const ll linf = (ll)1e18 + 7;
const int dx[] = {-1, 0, 1, 0, 1, -1, -1, 1}, dy[] = {0, 1, 0, -1, 1, -1, 1, -1};

using namespace std;

int n, k;
vector <int> g[N];
bool ok[N][N];

int dp[N][N][2];
int dp1[N][N][2];



int nxt(int x) {
	if (x == 1) return n;
	return x - 1;
}
int prv(int x) {
	if (x == n) return 1;
	return x + 1;
}
int calc(int A, int B, int t) {
	if (~dp[A][B][t]) return dp[A][B][t];
	int res = 0;
	if (t) {
		for (int i = nxt(A); i != B; i = nxt(i)) {
			if (ok[B][i]) {
				res = max(res, calc(A, i, 1) + 1);
				res = max(res, calc(B, i, 0) + 1);
			}
		}
	}
	else {
		for (int i = prv(A); i != B; i = prv(i)) {
			if (ok[B][i]) {
				res = max(res, calc(A, i, 0) + 1);
				res = max(res, calc(B, i, 1) + 1);
			}		
		}
	}
	return dp[A][B][t] = res;
}	

int f(int A, int B, int t) {
	if (A == B) return 0;
	if (~dp1[A][B][t]) return dp1[A][B][t];
	int res = -inf;
	if (t) {
		for (int i = nxt(A); ; i = nxt(i)) {
			if (ok[A][i]) res = max(res, f(i, B, 1) + 1);
			if (i == B) break;
		}
	}
	else {
		for (int i = prv(A); ; i = prv(i)) {
			if (ok[A][i]) res = max(res, f(i, B, 0) + 1);
			if (i == B) break;
		}
	}
	return dp1[A][B][t] = res;
}

int res[N];

bool on(int C, int A, int B) {
	if (A <= B) {
		return A < C && C < B;
	} else {
		swap(A, B);
		return !(A <= C && C <= B);
	}
}
bool sol(int C, int A, int B) {
	if (A <= B) {
		return !(A <= C && C <= B);
	} else {
		swap(A, B);
		return  A < C && C < B;
	}
}
void solve() {
	memset(dp1, -1, sizeof(dp1));
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
	 		f(i, j, 0), f(i, j, 1);
		}
	}
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			if (ok[i][j]) {
				for (int r = nxt(j); r != i; r = nxt(r)) {
					for (auto to : g[r]) {
						if (sol(to, i, j)) res[i] = max(res[i], 2 + dp1[j][r][1] + max(dp[j][to][0], dp[i][to][1]));
					}
				}
				for (int l = prv(j); l != i; l = prv(l)) {
					for (auto to : g[l]) {
						if (on(to, i, j)) res[i] = max(res[i], 2 + dp1[j][l][0] + max(dp[j][to][1], dp[i][to][0]));
					}
				}
			}
		}
	}
}
int main() {
	#ifdef IOI2018
		freopen ("in.txt", "r", stdin);
	#endif
	scanf ("%d%d", &n, &k);
	for (int i = 1; i <= n; i++) {
		int to;
		while (scanf ("%d", &to) && to) {
			ok[i][to] = 1;
			g[i].pb(to);
		}
	}
	memset(dp, -1, sizeof(dp));
	int mx = 0, opt = -1;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			calc(i, j, 0), calc(i, j, 1);
			if (ok[i][j]) res[i] = max(res[i], max(calc(i, j, 0), calc(i, j, 1)) + 1);
			
		}
	}
	if (k == 1) solve();
	int p = max_element(res + 1, res + 1 + n) - res;
	printf ("%d\n%d", res[p], p);
	ioi
}

Compilation message (stderr)

race.cpp: In function 'int main()':
race.cpp:147:6: warning: unused variable 'mx' [-Wunused-variable]
  int mx = 0, opt = -1;
      ^
race.cpp:147:14: warning: unused variable 'opt' [-Wunused-variable]
  int mx = 0, opt = -1;
              ^
race.cpp:138:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d%d", &n, &k);
                        ^

• Subtask 1: 75 / 100