1 solutions

  • 0
    @ 2026-1-26 17:35:29
    #include<bits/stdc++.h>
    using namespace std;
    long long n,dp[1000010][9],mod=998244353,ans;
    int main()
    {
    	cin>>n;
    	for(int i=1;i<=9;i++)
    	{
    		dp[1][i]=1;
    	}
    	for(int i=2;i<=n;i++)
    	{
    		for(int j=1;j<=9;j++)
    		{
    			if(j==1)
    			{
    				dp[i][j]=dp[i-1][j]+dp[i-1][j+1];
    			}
    			else if(j==9)
    			{
    				dp[i][j]=dp[i-1][j]+dp[i-1][j-1];
    			}
    			else
    			{
    				dp[i][j]=dp[i-1][j-1]+dp[i-1][j]+dp[i-1][j+1];
    			}
    			dp[i][j]%=mod;
    		}
    	}
    	for(int i=1;i<=9;i++)
    	{
    		ans=(ans+dp[n][i])%mod;
    	}
    	cout<<ans;
    	return 0;
    }
    
    • 1

    Information

    ID
    2791
    Time
    1000ms
    Memory
    256MiB
    Difficulty
    5
    Tags
    # Submissions
    8
    Accepted
    4
    Uploaded By