Submission #129163

#	Time	Username	Problem	Language	Result	Execution time	Memory
129163		mohammedehab2002	Lamps (JOI19_lamps)	C++11	100 / 100	248 ms	75080 KiB

lamp

#include <iostream>
using namespace std;
int dp[4][4][1000005],tpt[2][1000005];
int main()
{
	int n;
	string a,b;
	cin >> n >> a >> b;
	for (int j=0;j<4;j++)
	{
		for (int k=0;k<4;k++)
		dp[j][k][0]=1e9;
	}
	dp[3][3][0]=0;
	tpt[0][0]=1e9;
	tpt[1][0]=1e9;
	for (int i=0;i<=n;i++)
	{
		int mn=min(tpt[0][i],tpt[1][i]),md[4];
		for (int j=0;j<4;j++)
		md[j]=1e9;
		md[2]=min(md[2],mn);
		md[0]=min(md[0],tpt[0][i]);
		md[1]=min(md[1],tpt[1][i]);
		for (int j=0;j<4;j++)
		{
			for (int k=0;k<4;k++)
			{
				dp[j][k][i+1]=1e9;
				mn=min(mn,dp[j][k][i]);
				md[j]=min(md[j],dp[j][k][i]);
				md[k]=min(md[k],dp[j][k][i]);
			}
		}
		if (i==n)
		{
			printf("%d",mn);
			return 0;
		}
		if (a[i]==b[i])
		dp[3][3][i+1]=mn;
		else
		dp[2][3][i+1]=min(mn+1,md[2]);
		bool cur=b[i]-'0';
		dp[!cur][2][i+1]=min(min(min(md[!cur]+1,md[2]+1),min(dp[!cur][2][i],mn+2)),tpt[!cur][i]);
		dp[2][cur][i+1]=min(min(min(md[2]+1,md[cur]+1),min(dp[2][cur][i],mn+2)),tpt[cur][i]);
		dp[cur][3][i+1]=min(md[cur],mn+1);
		tpt[cur][i+1]=1e9;
		tpt[!cur][i+1]=min(min(min(tpt[!cur][i],mn+3),min(md[2],md[!cur])+2),min(min(dp[2][!cur][i],dp[!cur][2][i]),tpt[cur][i])+1);
	}
}

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 4 / 4
• Subtask 4: 49 / 49