LCT

  1 /**************************************************************  2     Problem: 3282  3     User: Tunix  4     Language: C++  5     Result: Accepted  6     Time:2596 ms  7     Memory:8596 kb  8 ****************************************************************/  9   10 //BZOJ 3282 11 #include<cstdio> 12 #include<vector> 13 #include<cstring> 14 #include<cstdlib> 15 #include<iostream> 16 #include<algorithm> 17 #define rep(i,n) for(int i=0;i<n;++i) 18 #define F(i,j,n) for(int i=j;i<=n;++i) 19 #define D(i,j,n) for(int i=j;i>=n;--i) 20 #define pb push_back 21 using namespace std; 22 const int N=300010; 23 #define debug 24   25 int c[N][2],fa[N],v[N],s[N],st[N],top=0; 26 bool rev[N]; 27 int n,m; 28   29 void Push_up(int x){ 30     int l=c[x][0],r=c[x][1]; 31     s[x]=s[l]^s[r]^v[x]; 32 } 33 void Push_down(int x){ 34     int l=c[x][0],r=c[x][1]; 35     if(rev[x]){ 36         rev[x]^=1; rev[l]^=1; rev[r]^=1; 37         swap(c[x][0],c[x][1]); 38     } 39 } 40 bool isroot(int x){ 41     return c[fa[x]][0]!=x && c[fa[x]][1]!=x; 42 } 43 void rotate(int x){ 44     int y=fa[x],z=fa[y],l=c[y][1]==x,r=l^1; 45     if (!isroot(y)) c[z][c[z][1]==y]=x; 46     fa[x]=z; fa[y]=x; fa[c[x][r]]=y; 47     c[y][l]=c[x][r]; c[x][r]=y; 48     Push_up(y); Push_up(x); 49 } 50 void splay(int x){ 51     top=0; st[top++]=x; 52     for(int i=x;!isroot(i);i=fa[i]) 53         st[top++]=fa[i]; 54     while(top--) Push_down(st[top]); 55       56     while(!isroot(x)){ 57         int y=fa[x],z=fa[y]; 58         if (!isroot(y)){ 59             if (c[y][0]==x^c[z][0]==y) rotate(x); 60             else rotate(y); 61         } 62         rotate(x); 63     } 64 } 65 void access(int x){ 66     for(int t=0;x;t=x,x=fa[x]) 67         splay(x),c[x][1]=t,Push_up(x); 68 } 69 void makeroot(int x){ 70     access(x); splay(x); rev[x]^=1; 71 } 72 int find(int x){ 73     access(x); splay(x); 74     while(c[x][0]) x=c[x][0]; 75     return x; 76 } 77 void cut(int x,int y){ 78     makeroot(x); access(y); splay(y); 79     if (c[y][0]==x) c[y][0]=fa[x]=0; 80 } 81 void link(int x,int y){ 82     makeroot(x); fa[x]=y; 83 } 84 //LCT end 85 int main(){ 86     #ifndef ONLINE_JUDGE 87     freopen("file.in","r",stdin); 88 //  freopen("file.out","w",stdout); 89     #endif 90     scanf("%d%d",&n,&m); 91     F(i,1,n) {scanf("%d",&v[i]); s[i]=v[i];} 92       93     int c,x,y; 94     F(i,1,m){ 95         scanf("%d%d%d",&c,&x,&y); 96         switch(c){ 97             case 0:makeroot(x); access(y); splay(y); printf("%d\n",s[y]);break; 98             case 1:if (find(x)!=find(y)) link(x,y);break; 99             case 2:if (find(x)==find(y)) cut(x,y);break;100             case 3:access(x); splay(x); v[x]=y; Push_up(x);break;101         }102     }103     return 0;104 }