Submission #132263

#	Time	Username	Problem	Language	Result	Execution time	Memory
132263		amoo_safar	Sailing Race (CEOI12_race)	C++14	100 / 100	2081 ms	2756 KiB

race

#include<bits/stdc++.h>
#define pb push_back

using namespace std;

typedef long long ll;

const int Maxn = 5e2 + 10;
const int Inf = 10000;
bool G[Maxn][Maxn];

int n, dp[Maxn][Maxn][2], dp2[Maxn], dp3[Maxn];

int nxt(int y){
	return (y == n - 1 ? 0 : y + 1);
}
int prev(int y){
	return (y == 0 ? n - 1 : y- 1);
}


int main(){
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	int k;
	cin >> n >> k;
	
	int adj;
	for(int i = 0; i < n; i++){
		while(true){
			cin >> adj;
			adj --;
			if(adj == -1) break;
			G[i][adj] = true;
		}
	}
	
	for(int l = 1; l <= n; l++){
		for(int i = 0; i < n; i++){
			int j = (i + l) % n;
			dp[i][j][0] = 0;
			for(int k = nxt(i); k != j; k = nxt(k)){
				if(G[i][k]) dp[i][j][0] = max( dp[i][j][0], max(dp[k][j][0], dp[k][i][1]) + 1);
			}
			j = (i - l + n) % n;
			dp[i][j][1] = 0;
			for(int k = prev(i); k != j; k = prev(k)){
				if(G[i][k]) dp[i][j][1] = max( dp[i][j][1], max(dp[k][j][1], dp[k][i][0]) + 1);
			}
		}
	}
	int ans = 0, st = 0, res;
	for(int i = 0; i < n; i++){
		ans = max(ans, dp[i][i][0]);
		if(ans == dp[i][i][0]) st = i;
	}
	
	if(k == 1){
		for(int sec = 0; sec < n; sec ++){
			fill(dp2, dp2 + Maxn, -Inf);
			dp2[sec] = 0;
			for(int fir = nxt(sec); fir != sec; fir = nxt(fir)){
				for(int bef = sec; bef != fir; bef = nxt(bef)){
					if(G[bef][fir]) dp2[fir] = max(dp2[fir], dp2[bef] + 1);
				}
			}
			fill(dp3, dp3 + Maxn, -Inf);
			for(int fir = nxt(sec); fir != sec; fir = nxt(fir)){
				
				if((fir != nxt(sec)) && (G[fir][sec])){
					res = 0;
					for(int P = nxt(fir); P != sec; P = nxt(P)){
						res = max(res, 1 + dp3[P] + max(dp[P][sec][0], dp[P][fir][1]) );
					}
					if(res > ans){
						ans = res;
						st = fir;
					}
				}
				for(int i = 0; i < n; i++) if(G[fir][i]) dp3[i] = max(dp3[i], dp2[fir] + 1);
			}
			
			fill(dp2, dp2 + Maxn, -Inf);
			dp2[sec] = 0;
			for(int fir = prev(sec); fir != sec; fir = prev(fir)){
				for(int bef = sec; bef != fir; bef = prev(bef)){
					if(G[bef][fir]) dp2[fir] = max(dp2[fir], dp2[bef] + 1);
				}
			}
			fill(dp3, dp3 + Maxn, -Inf);
			for(int fir = prev(sec); fir != sec; fir = prev(fir)){
				
				if((fir != prev(sec)) && (G[fir][sec])){
					res = 0;
					for(int P = prev(fir); P != sec; P = prev(P)){
						res = max(res, 1 + dp3[P] + max(dp[P][sec][1], dp[P][fir][0]) );
					}
					if(res > ans){
						ans = res;
						st = fir;
					}
				}
				for(int i = 0; i < n; i++) if(G[fir][i]) dp3[i] = max(dp3[i], dp2[fir] + 1);
			}
			
		}
	}
	
	cout << ans << '\n' << st + 1 << '\n';
	
	return 0;
}
/*
7 1
5 0
5 0
7 0
3 0
4 0
4 3 0
2 1 0
*/

• Subtask 1: 100 / 100