Submission #265290

#	Time	Username	Problem	Language	Result	Execution time	Memory
265290		TadijaSebez	Sailing Race (CEOI12_race)	C++11	75 / 100	3099 ms	3320 KiB

race

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
void ckmx(int&x,int y){x=max(x,y);}
const int N=505;
vector<int> E[N];
int dp[N][N][2],n,k,tmp[N];
bool was[N][N][2];
int on(int l,int r,int v){
	return (l<=r&&l<=v&&r>=v)||(l>r&&(v<=r||v>=l));
}
int DP(int l,int r,int side){
	if(was[l][r][side])return dp[l][r][side];
	int u=side==0?l:r;
	was[l][r][side]=1;
	int L=side==0?(l==n?1:l+1):l;
	int R=side==1?(r==1?n:r-1):r;
	for(int v:E[u]){
		if(on(l,r,v)){
			ckmx(dp[l][r][side],1+max(DP(L,v,1),DP(v,R,0)));
		}
	}
	return dp[l][r][side];
}
int main(){
	scanf("%i %i",&n,&k);
	for(int i=1;i<=n;i++){
		while(1){
			int j;
			scanf("%i",&j);
			if(j==0)break;
			E[i].pb(j);
		}
	}
	int ans=-1,idx=0;
	for(int i=1;i<=n;i++){
		int now=DP(i,i==1?n:i-1,0);
		if(k==1){
			auto nxt=[&](int x){return x==n?1:x+1;};
			auto pre=[&](int x){return x==1?n:x-1;};
			for(int j:E[i]){
				for(int l=1;l<=n;l++)tmp[l]=0;
				tmp[j]=1;
				for(int l=j;l!=i;l=nxt(l)){
					for(int r:E[l])if(r!=i&&r!=j){
						if(on(i,j,r))ckmx(now,tmp[l]+1+max(DP(nxt(i),r,1),DP(r,pre(j),0)));
						else ckmx(tmp[r],tmp[l]+1);
					}
				}
				for(int l=j;l!=i;l=pre(l)){
					for(int r:E[l])if(r!=i&&r!=j){
						if(on(j,i,r))ckmx(now,tmp[l]+1+max(DP(nxt(j),r,1),DP(r,pre(i),0)));
						else ckmx(tmp[r],tmp[l]+1);
					}
				}
			}
		}
		if(now>ans)ans=now,idx=i;
	}
	printf("%i\n%i\n",ans,idx);
	return 0;
}

Compilation message (stderr)

race.cpp: In function 'int main()':
race.cpp:26:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   26 |  scanf("%i %i",&n,&k);
      |  ~~~~~^~~~~~~~~~~~~~~
race.cpp:30:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   30 |    scanf("%i",&j);
      |    ~~~~~^~~~~~~~~

• Subtask 1: 75 / 100