51 lines
947 B
C++
51 lines
947 B
C++
#include<cstdio>
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#include<algorithm>
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#include<cstring>
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using namespace std;
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const int maxn=1000005;
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int T,n,x[maxn],y[maxn],z[maxn],a[maxn*2],cnt,fa[maxn*2];
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inline int ff(int u)
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{
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int a=u,b;
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while(u!=fa[u]) u=fa[u];
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while(a!=u)
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{
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b=fa[a];
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fa[a]=u;
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a=b;
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}
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return u;
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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",&T);
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while(T-->0)
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{
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scanf("%d",&n);
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for(int i=1;i<=n;i++) scanf("%d%d%d",&x[i],&y[i],&z[i]);
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cnt=0;
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for(int i=1;i<=n;i++) a[++cnt]=x[i],a[++cnt]=y[i];
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sort(a+1,a+1+cnt);
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cnt=unique(a+1,a+1+cnt)-(a+1);
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for(int i=1;i<=n;i++)
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{
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x[i]=lower_bound(a+1,a+1+cnt,x[i])-a;
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y[i]=lower_bound(a+1,a+1+cnt,y[i])-a;
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}
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for(int i=1;i<=cnt;i++) fa[i]=i;
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int flg=1;
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for(int i=1;i<=n;i++) if(z[i]==1)
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{
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int a=ff(x[i]),b=ff(y[i]);
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if(a!=b) fa[a]=b;
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}
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for(int i=1;i<=n;i++) if(z[i]==0)
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if(ff(x[i])==ff(y[i])) { flg=0; break; }
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puts(flg?"YES":"NO");
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}
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return 0;
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}
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