74 lines
1.0 KiB
C++
74 lines
1.0 KiB
C++
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#include<cstdio>
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#include<cstring>
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using namespace std;
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const int mod=998244353,N=21;
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char s[N][30];
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int mask[N];
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long long ans=0;
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long long qpow(long long n,int l )
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{
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long long res=1;
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while(l>0)
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{
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if(l&1)
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{
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res=res*n%mod;
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}
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l>>=1;
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n=n*n%mod;
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}
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return res;
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}
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int Count(int x)
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{
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int cnt=0;//cnt=0!
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while(x>0)
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{
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if(x&1)
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{
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cnt++;
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}
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x>>=1;
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}
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return cnt;
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}
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int main()
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{
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int n,l;
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scanf("%d%d",&n,&l);
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for(int i=0; i<n; i++)//0~n-1 -> 1~n
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{
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scanf("%s",s[i]);
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int len=strlen(s[i]);
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for(int j=0; j<len; j++)
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{
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mask[i]|=(1<<(s[i][j]-'a'));
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}
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}
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for(int i=1;i<(1<<n);i++)//ѡ<><D1A1><EFBFBD>ļ<EFBFBD><C4BC><EFBFBD>
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{
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//ch<63><68><EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD><DDA3><EFBFBD><EFBFBD>еIJ<D0B5><C4B2><EFBFBD> <20><>cntѡ<74>˼<EFBFBD><CBBC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϣ<EFBFBD>
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int ch=(1<<26)-1,cnt=0;//1<<26 ->1<<j
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for(int j=0;j<n;j++)
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{
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if(i&(1<<j))
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{
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cnt++;
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ch&=mask[j];
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}
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}
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//ż<><C5BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>+
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if(cnt&1)
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{
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ans=(ans+qpow(Count(ch),l))%mod;
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}
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else
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{
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// ans = (ans + (mod - qpow(Count(ch), l)) % mod) % mod;
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ans=(ans+mod-qpow(Count(ch),l))%mod;
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}
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}
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printf("%lld",ans);
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return 0;
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}
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