P1955 [NOI2015]程序自动分析[离散化+并查集]
一看就是离散化，先去满足相等的条件，相等即为两点联通，或者说在同一个集合内。再看不相等，只有两元素在同一集合才不满足。裸的disjoint-set直接上，常数巨大什么的不管啦。
1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<cmath> 5 #include<algorithm> 6 #include<queue> 7 #define dbg(x) cerr<<#x<<" = "<<x<<endl 8 #define ddbg(x,y) cerr<<#x<<" = "<<x<<" "<<#y<<" = "<<y<<endl 9 using namespace std; 10 typedef long long ll; 11 template<typename T>inline char MIN(T&A,T B){return A>B?A=B,1:0;} 12 template<typename T>inline char MAX(T&A,T B){return A<B?A=B,1:0;} 13 template<typename T>inline T _min(T A,T B){return A<B?A:B;} 14 template<typename T>inline T _max(T A,T B){return A>B?A:B;} 15 template<typename T>inline T read(T&x){ 16 x=0;int f=0;char c;while(!isdigit(c=getchar()))if(c=='-')f=1; 17 while(isdigit(c))x=x*10+(c&15),c=getchar();return f?x=-x:x; 18 } 19 const int N=100000+7; 20 struct Remilia_Scarlet{ 21 int x,y,d; 22 inline bool operator <(const Remilia_Scarlet&A)const{ 23 return d>A.d; 24 } 25 }q[N]; 26 int A[N<<1],fa[N<<1]; 27 int T,n,m,fx,fy,flag; 28 inline int Get(int x){return fa[x]^x?fa[x]=Get(fa[x]):x;} 29 30 int main(){//freopen("test.in","r",stdin);//freopen("test.out","w",stdout); 31 read(T);while(T--){ 32 read(n);m=0;flag=0; 33 for(register int i=1;i<=n;++i)A[++m]=read(q[i].x),A[++m]=read(q[i].y),read(q[i].d); 34 sort(A+1,A+m+1);m=unique(A+1,A+m+1)-A-1;sort(q+1,q+n+1); 35 for(register int i=1;i<=m;++i)fa[i]=i; 36 for(register int i=1;i<=n;++i){ 37 if(q[i].d){ 38 fx=Get(lower_bound(A+1,A+m+1,q[i].x)-A),fy=Get(lower_bound(A+1,A+m+1,q[i].y)-A); 39 if(fx^fy)fa[fx]=fy;//ddbg(fx,fy); 40 } 41 else{ 42 fx=Get(lower_bound(A+1,A+m+1,q[i].x)-A),fy=Get(lower_bound(A+1,A+m+1,q[i].y)-A); 43 if(fx^fy)continue; 44 flag=1;break; 45 } 46 } 47 flag?printf("NO\n"):printf("YES\n"); 48 } 49 return 0; 50 }
