Title Description
Small $ w $ accidentally saw a $ DAG $.
This has $ $ $ m $ the DAG layer, only one source point of the first layer, the last layer is only a sink, each of the remaining layer has $ k $ nodes.
Now small $ $ W can invert each connected between the first $ i (1 <i <n-1 ) $ layer and $ i + 1 $ layer side. I.e. from the original $ (i, k_1) $ connected to the $ (i + 1, k_2) $ edges becomes from $ (i, k_2) $ connected to the $ (i + 1, k_1) $.
I ask him how many negated program, the number of paths from source to sink into an even number?
The answer modulo $ 998 244 353 $.
Input Format
Line two integers $ m, k $.
Next $ m-1 $ row, the first row and the last row has $ k $ integer $ 0 $ or $ 1 $, the rest of each line has $ k ^ 2 $ integer $ 0 $ or $ 1 $, the $ (J- 1) \ times k + t $ represents integers $ (i, j) $ to $ (i + 1, t) $ has no edges.
Output Format
A row of integer answer.
Sample
Sample input:
5 3
1 0 1
0 1 0 1 1 0 0 0 1
0 1 1 1 0 0 0 1 1
0 1 1
Sample output:
4
Data range and tips
$ 20 \% $ data satisfies $ n \ leqslant 10, k \ leqslant 2 $.
$ 40 \% $ data satisfies $ n \ leqslant 10 ^ 3, k \ leqslant 2 $.
$ 60 \% $ data satisfies $ m \ leqslant 10 ^ 3, k \ leqslant 5 $.
$ 100 \ $% of the data satisfies $ 4 \ leqslant m \ leqslant 10 ^ 4, k \ leqslant 10 $.
answer
$ K $ found little, considering the DP-shaped pressure $ $, set $ dp [i] [s] $ $ I $ indicates the status of the line, the edge points can be connected to the program number of $ s $.
Transfer with a memory search to search from back to front.
Time complexity: $ \ Theta (NK2 ^ K) $.
Expectations score: $ 100 $ points.
Actual score: $ 100 $ points.
Code time
#include<bits/stdc++.h>
using namespace std;
const int mod=998244353;
int M,K,S;
int Map[2][10001][11],a[11],g[1025];
long long dp[10001][1025];
int lowbit(int x){return x&-x;}
long long dfs(int x,int s)
{
if(dp[x][s]!=-1)return dp[x][s];
if(x==2)
{
dp[x][s]=1;
for(int i=1;i<=K;i++)dp[x][s]^=a[i]&((s&(1<<(i-1)))!=0);
}
else
{
int ls=0,rs=0;
for(int i=1;i<=K;i++)
{
ls|=g[Map[0][x-1][i]&s]<<(i-1);
rs|=g[Map[1][x-1][i]&s]<<(i-1);
}
dp[x][s]=(dfs(x-1,ls)+dfs(x-1,rs))%mod;
}
return dp[x][s];
}
int main()
{
memset(dp,-1,sizeof(dp));
scanf("%d%d",&M,&K);
for(int i=1;i<(1<<K);i++)g[i]=g[i-lowbit(i)]^1;
for(int i=1;i<=K;i++)scanf("%d",&a[i]);
for(int i=2;i<M-1;i++)
for(int j=1;j<=K;j++)
for(int k=1;k<=K;k++)
{
int x;scanf("%d",&x);
Map[0][i][j]|=x<<(k-1);
Map[1][i][k]|=x<<(j-1);
}
for(int i=1;i<=K;i++)
{
int x;
scanf("%d",&x);
S|=x<<(i-1);
}
printf("%lld",dfs(M-1,S));
return 0;
}
rp ++