57 lines
940 B
C++
57 lines
940 B
C++
#include<cstdio>
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#include<cstring>
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const int N=52;
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int g[N][N];
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int c[N];
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inline int id(char a1, char a2)
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{
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return ((a1-'A')<<1)+(a2=='+'?0:1);
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}
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inline void connect(char a1,char a2,char b1,char b2)
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{
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if(a1=='0'||b1=='0') return;
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int u=id(a1,a2)^1,v=id(b1,b2);
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g[u][v] = 1;
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}
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bool toposort(int u)
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{
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c[u]=-1;
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for(int v=0;v<N;v++)
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if(g[u][v])
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{
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if(c[v]<0) return true;
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else if(!c[v]&&toposort(v)) return true;
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}
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c[u]=1;
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return false;
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}
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inline bool cycle()
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{
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memset(c,0,sizeof(c));
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for (int i=0;i<N;i++)
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if(!c[i]&&toposort(i)) return true;
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return false;
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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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int n;
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while(scanf("%d",&n)==1&&n)
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{
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memset(g,0,sizeof(g));
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while(n--)
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{
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char s[10];
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scanf("%s",s);
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for(int i=0;i<4;i++)
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for(int j=0;j<4;j++)
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if(i!=j)
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connect(s[i<<1],s[(i<<1)+1],s[j<<1],s[(j<<1)+1]);
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}
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printf("%s\n",cycle()?"unbounded":"bounded");
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}
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return 0;
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}
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