link cut tree
模板题
link cut tree不都是模板题嘛？(雾
1 #include<algorithm> 2 #include<iostream> 3 #include<cstdlib> 4 #include<cstring> 5 #include<cstdio> 6 #include<string> 7 #include<cmath> 8 #include<ctime> 9 #include<queue> 10 #include<stack> 11 #include<map> 12 #include<set> 13 #define rre(i,r,l) for(int i=(r);i>=(l);i--) 14 #define re(i,l,r) for(int i=(l);i<=(r);i++) 15 #define Clear(a,b) memset(a,b,sizeof(a)) 16 #define inout(x) printf("%d",(x)) 17 #define douin(x) scanf("%lf",&x) 18 #define strin(x) scanf("%s",(x)) 19 #define LLin(x) scanf("%lld",&x) 20 #define op operator 21 #define CSC main 22 typedef unsigned long long ULL; 23 typedef const int cint; 24 typedef long long LL; 25 using namespace std; 26 void inin(int &ret) 27 { 28 ret=0;int f=0;char ch=getchar(); 29 while(ch<'0'||ch>'9'){if(ch=='-')f=1;ch=getchar();} 30 while(ch>='0'&&ch<='9')ret*=10,ret+=ch-'0',ch=getchar(); 31 ret=f?-ret:ret; 32 } 33 int n,q,w[30030],ch[30030][2],fa[30030],sum[30030],rev[30030]; 34 bool isroot(int x){return ch[fa[x]][0]!=x&&ch[fa[x]][1]!=x;} 35 void maintain(int x){if(x)sum[x]=w[x]+sum[ch[x][0]]+sum[ch[x][1]];} 36 void rotate(int x) 37 { 38 int y=fa[x],z=fa[y]; 39 if(!isroot(y))ch[z][ch[z][1]==y]=x; 40 fa[x]=z,fa[y]=x; 41 int d=ch[y][1]==x; 42 fa[ch[x][d^1]]=y; 43 ch[y][d]=ch[x][d^1]; 44 ch[x][d^1]=y; 45 maintain(y);maintain(x); 46 } 47 void down(int x) 48 { 49 if(rev[x]) 50 { 51 swap(ch[x][0],ch[x][1]); 52 rev[ch[x][0]]^=1; 53 rev[ch[x][1]]^=1; 54 rev[x]=0; 55 } 56 } 57 int sta[30030],top; 58 void splay(int x) 59 { 60 top=0;int xx=x;sta[++top]=xx; 61 while(!isroot(xx))sta[++top]=fa[xx],xx=fa[xx]; 62 while(top)down(sta[top--]); 63 while(!isroot(x)) 64 { 65 int y=fa[x],z=fa[y]; 66 if(!isroot(y)) 67 if((ch[y][1]==x)^(ch[z][1]==y))rotate(x); 68 else rotate(y);else ; 69 rotate(x); 70 } 71 } 72 void access(int x) 73 { 74 int temp=0; 75 while(x) 76 { 77 splay(x); 78 ch[x][1]=temp;maintain(x); 79 temp=x,x=fa[x]; 80 } 81 } 82 void reverse(int x) 83 { 84 access(x),splay(x),rev[x]^=1; 85 } 86 void link(int x,int y) 87 { 88 reverse(x),fa[x]=y; 89 } 90 void cut(int x,int y) 91 { 92 reverse(x),access(y),fa[x]=ch[y][0]=0;maintain(y); 93 } 94 int find(int x) 95 { 96 access(x);splay(x); 97 while(ch[x][0])x=ch[x][0]; 98 return x; 99 } 100 int main() 101 { 102 inin(n);char ss[22]; 103 re(i,1,n)inin(w[i]),sum[i]=w[i]; 104 inin(q); 105 re(i,1,q) 106 { 107 strin(ss);int a,b;inin(a),inin(b); 108 if(ss[0]=='b') 109 { 110 if(find(a)==find(b))cout<<"no "; 111 else 112 { 113 cout<<"yes "; 114 link(a,b); 115 } 116 } 117 else if(ss[0]=='p') 118 { 119 splay(a),w[a]=b,maintain(a); 120 } 121 else if(ss[0]=='e') 122 { 123 if(find(a)!=find(b)){cout<<"impossible ";continue;} 124 reverse(a),access(b),splay(b); 125 printf("%d ",sum[b]); 126 } 127 } 128 return 0; 129 }