29 lines
562 B
C++
29 lines
562 B
C++
#include<cstdio>
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#include<cassert>
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#include<algorithm>
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using namespace std;
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int n,tot,inv,lg[1<<15]; char mp[15][15];
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void dfs(int dep,int M,int L,int R)
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{
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if(dep==n) { tot++; return; }
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int can=M|L|R;
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for(int it=inv&(can^inv);it;it-=it&-it)
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{
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int i=lg[it&-it];
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if(mp[dep][i]!='.') dfs(dep+1,M|(1<<i),(L|(1<<i))<<1,(R|(1<<i))>>1);
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}
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}
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int main()
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{
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#ifdef local
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freopen("pro.in","r",stdin);
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#endif
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scanf("%d",&n);
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for(int i=0;i<n;i++) scanf("%s",mp[i]);
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inv=(1<<n)-1;
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for(int i=0;i<n;i++) lg[1<<i]=i;
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dfs(0,0,0,0);
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printf("%d\n",tot);
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return 0;
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}
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