Submission #375299

#	Time	Username	Problem	Language	Result	Execution time	Memory
375299		YJU	Sailing Race (CEOI12_race)	C++14	15 / 100	459 ms	3564 KiB

race

#include<bits/stdc++.h>
#pragma GCC optimize("unroll-loops,no-stack-protector,Ofast")
using namespace std;
typedef int ll;
typedef pair<ll,ll> pll;
typedef long double ld;
const ll N=5e2+5;
const ll MOD=1e9+7;
const ld pi=acos(-1);
#define REP(i,n) for(int i=0;i<n;++i)
#define REP1(i,n) for(int i=1;i<=n;++i)
#define pb push_back
#define mp make_pair
#define X first
#define Y second
#define lwb lower_bound
#define SZ(_a) (ll)_a.size()

ll n,type,grid[N][N],x,dp[N][N][2];

ll ansm,anss;

void upd(ll ans,ll id){
	if(ans>=ansm){
		ansm=ans,anss=id;
	}
}

int main(){
	ios_base::sync_with_stdio(0);cin.tie(0);
	cin>>n>>type;
	REP(i,n){
		while(1){
            cin>>x;
            if(x==0)break;
            grid[i][x-1]=1;
		}
	}
	for(int len=2;len<n;len++){
        for(int i=0,j=(i+len>=n?i+len-n:i+len);i<n;i++,j=(j+1>=n?0:j+1)){
            for(int k=(i+1>=n?0:i+1);k!=j;k=(k+1>=n?0:k+1)){
				//i,j,0 means boat is now at i
				//i,j,1,means boat is now at j
                dp[i][j][0]=max(dp[i][j][0],(grid[i][k]?1+max(dp[i][k][1],dp[k][j][0]):0));
                dp[i][j][1]=max(dp[i][j][1],(grid[j][k]?1+max(dp[i][k][1],dp[k][j][0]):0));
            }
        }
	}
	REP(i,n)REP(j,n){
		if(i==j)continue;
		if(grid[i][j]){
			//cout<<i<<" "<<j<<" "<<dp[i][j][1]<<" "<<dp[j][i][0]<<"\n";
            upd(max(dp[i][j][1],dp[j][i][0])+1,i);
		}
	}
	cout<<ansm<<"\n"<<anss<<"\n";
	return 0;
}
/*
7 1
5 0
5 0
7 0
3 0
4 0
4 3 0
2 1 0


*/

• Subtask 1: 15 / 100