Submission #341291

#	Time	Username	Problem	Language	Result	Execution time	Memory
341291		ogibogi2004	Nafta (COI15_nafta)	C++14	34 / 100	1100 ms	56536 KiB

nafta

#include<bits/stdc++.h>
using namespace std;
const int MAXN=2048;
const int INF=1e9;
int pref[MAXN][MAXN];
int n,m,val,maxy;
char c[MAXN][MAXN];
int dp[MAXN][MAXN];
int opt[MAXN][MAXN];
bool vis[MAXN][MAXN];
int dx[4]={-1,1,0,0};
int dy[4]={0,0,-1,1};
void dfs(int x,int y)
{
	vis[x][y]=1;
	maxy=max(maxy,y);
	val+=c[x][y]-'0';
	for(int l=0;l<4;++l)
	{
		int x1=x+dx[l];
		int y1=y+dy[l];
		if(x1<1||y1<1||x1>n||y1>m)continue;
		if(c[x1][y1]=='.')continue;
		if(vis[x1][y1])continue;
		dfs(x1,y1);
	}
}
void calc(int d,int idx,int optl,int optr)
{
	int sum=0;
	for(int i=idx;i>=optl;--i)
	{
		sum+=pref[i][m]-pref[i][idx-1];
	}
	for(int i=optl;i<=optr&&i<idx;++i)
	{
		sum-=pref[i][m]-pref[i][idx-1];
		if(dp[i][d-1]+sum>dp[idx][d])
		{
			dp[idx][d]=dp[i][d-1]+sum;
			opt[idx][d]=i;
		}
	}
}
void solve(int d,int l,int r,int optl,int optr)
{
	if(l>r)return;
	int mid=(l+r)/2;
	//cout<<mid<<" "<<optl<<" "<<optr<<endl;
	calc(d,mid,optl,optr);
	solve(d,mid+1,r,opt[mid][d],optr);
	solve(d,l,mid-1,optl,opt[mid][d]);
}
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	cin>>n>>m;
	for(int i=1;i<=n;++i)
	{
		for(int j=1;j<=m;++j)
		{
			cin>>c[i][j];
		}
	}
	//cout<<"*\n";
	for(int j=1;j<=m;++j)
	{
		for(int i=1;i<=n;++i)
		{
			if(vis[i][j])continue;
			if(c[i][j]=='.')continue;
			val=0;maxy=0;
			dfs(i,j);
			pref[j][maxy]+=val;
		}
	}
	//cout<<"*\n";
	for(int j=1;j<=m;++j)
	{
		for(int i=1;i<=m;++i)
		{
			pref[j][i]=pref[j][i]+pref[j][i-1];
		}
	}
	for(int i=0;i<=m;++i)
	{
		for(int j=0;j<=m;++j)
		{
			dp[i][j]=-INF;
		}
	}
	dp[0][0]=0;
	for(int k=1;k<=m;++k)
	{
		solve(k,1,m,0,m);
		int maxdp=0;
		for(int i=1;i<=m;++i)
		{
			maxdp=max(maxdp,dp[i][k]);
			//cout<<dp[i][k]<<" "<<opt[i][k]<<endl;
		}
		cout<<maxdp<<'\n';
	}
return 0;
}

• Subtask 1: 11 / 11
• Subtask 2: 23 / 23
• Subtask 3: 0 / 66