Submission #888069

#	Time	Username	Problem	Language	Result	Execution time	Memory
888069		amirhoseinfar1385	Collecting Stamps 3 (JOI20_ho_t3)	C++17	15 / 100	39 ms	145496 KiB

ho_t3

#include<bits/stdc++.h>
using namespace std;
const long long maxn=210,inf=1000000000000;
pair<long long,long long>dp[maxn][maxn][maxn];
long long n,allx[maxn],allt[maxn],L;
long long res=0;
long long fas(long long a,long long b){
	 if (b <= a)
        return (a - b);
    return L - (b- a);
}

void upddp(long long l,long long r){
	//cout<<l<<" "<<r<<" "<<dp[l][r][0].first<<" "<<dp[l][r][0].second<<"\n";
	long long ll=(l-1)+n,rr=r+1;
	ll%=n;
	rr%=n;
	for(long long i=0;i<n;i++){
		if(dp[l][r][i].first!=inf){
			//cout<<l<<" "<<r<<" "<<i<<" "<<dp[l][r][i].first<<" "<<dp[l][r][i].second<<'\n';
			dp[ll][r][i].first=min(dp[ll][r][i].first,dp[l][r][i].first+fas(allx[l],allx[ll]));
			dp[ll][r][i].second=min(dp[ll][r][i].second,dp[ll][r][i].first+fas(allx[r],allx[ll]));
			if(fas(allx[l],allx[ll])+dp[l][r][i].first<=allt[ll]){
				dp[ll][r][i+1].first=min(dp[ll][r][i+1].first,dp[l][r][i].first+fas(allx[l],allx[ll]));
				dp[ll][r][i+1].second=min(dp[ll][r][i+1].second,dp[ll][r][i].first+fas(allx[r],allx[ll]));
				res=max(res,i+1);
			}
			dp[l][rr][i].second=min(dp[l][rr][i].second,dp[l][r][i].second+fas(allx[rr],allx[r]));
			dp[l][rr][i].first=min(dp[l][rr][i].first,dp[l][rr][i].second+fas(allx[rr],allx[l]));
			if(fas(allx[rr],allx[r])+dp[l][r][i].second<=allt[rr]){
				dp[l][rr][i+1].second=min(dp[l][rr][i].second,dp[l][r][i].second+fas(allx[rr],allx[r]));
				dp[l][rr][i+1].first=min(dp[l][rr][i+1].first,dp[l][rr][i+1].second+fas(allx[rr],allx[l]));
				res=max(res,i+1);
			}
		}
	}
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	for(long long i=0;i<maxn;i++){
		for(long long j=0;j<maxn;j++){
			for(long long h=0;h<maxn;h++){
				dp[i][j][h]=make_pair(inf,inf);
			}
		}
	}
	cin>>n>>L;
	for(long long i=0;i<n;i++){
		cin>>allx[i];
	}
	for(long long i=0;i<n;i++){
		cin>>allt[i];
	}
	if(n==1){
		if(min(allx[0],fas(0,allx[0]))<=allt[0]){
			cout<<1<<endl;
			return 0;
		}
		cout<<0<<endl;
		return 0;
	}
	if(allx[0]<=allt[0]){
		dp[0][0][0]=dp[0][0][1]=make_pair(allx[0],allx[0]);
		res=1;
	}
	else{
		dp[0][0][0]=make_pair(allx[0],allx[0]);
	}
	if(fas(0,allx[n-1])<=allt[n-1]){
		dp[n-1][n-1][0]=dp[n-1][n-1][1]=make_pair(fas(0,allx[n-1]),fas(0,allx[n-1]));
		res=1;
	}
	else{
		dp[n-1][n-1][0]=make_pair(fas(0,allx[n-1]),fas(0,allx[n-1]));
	}
	for(long long i=0;i<n-1;i++){
		for(long long l=n-1;l>=0;l--){
			upddp(l,(l+i)%n);
		}
	}
	cout<<res<<"\n";
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 75