双倍经验双倍的幸福。。。
所以另一道是300大洋的世界T_T。。。虽然题目是一样的，不过2843数据范围小了一点。。。
都是lct基本操作
1 #include<cstdio> 2 #include<iostream> 3 #include<math.h> 4 using namespace std; 5 const int maxn=30233; 6 struct zs{ 7 int c[2],fa,sum,val; 8 bool rev; 9 }tree[maxn]; 10 int i,j,x,y,n,m; 11 int stack[maxn]; 12 char id[233]; 13 inline bool isroot(int x){return tree[tree[x].fa].c[0]!=x&&tree[tree[x].fa].c[1]!=x; 14 } 15 inline void update(int x){tree[x].sum=tree[tree[x].c[0]].sum+tree[x].val+tree[tree[x].c[1]].sum; 16 } 17 inline void pushdown(int x){ 18 if(!tree[x].rev)return; 19 int l=tree[x].c[0],r=tree[x].c[1]; 20 if(l)tree[l].rev^=1;if(r)tree[r].rev^=1;tree[x].rev^=1; 21 swap(tree[x].c[0],tree[x].c[1]); 22 } 23 inline void rotate(int x){ 24 int fa=tree[x].fa,gfa=tree[fa].fa; 25 if(!isroot(fa))tree[gfa].c[tree[gfa].c[1]==fa]=x; 26 int l=tree[fa].c[1]==x,r=l^1; 27 tree[fa].c[l]=tree[x].c[r];tree[x].c[r]=fa; 28 tree[fa].fa=x;tree[x].fa=gfa;tree[tree[fa].c[l]].fa=fa; 29 update(fa);update(x); 30 } 31 void splay(int x){ 32 int top=0,tmp=x;stack[++top]=x; 33 while(!isroot(tmp))stack[++top]=tree[tmp].fa,tmp=tree[tmp].fa; 34 while(top)pushdown(stack[top]),top--; 35 int fa,gfa; 36 while(!isroot(x)){ 37 fa=tree[x].fa,gfa=tree[fa].fa; 38 if(!isroot(fa)) 39 if((tree[gfa].c[0]==fa)^(tree[fa].c[0]==x))rotate(x); 40 else rotate(fa); 41 rotate(x); 42 } 43 } 44 inline void access(int x){ 45 int son=0; 46 while(x){ 47 splay(x);tree[x].c[1]=son; 48 update(x);son=x;x=tree[x].fa; 49 } 50 } 51 inline void makeroot(int x){ 52 access(x);splay(x);tree[x].rev^=1; 53 } 54 inline void cut(int x,int y){ 55 makeroot(x);access(y);splay(y);tree[y].c[0]=tree[x].fa=0; 56 } 57 inline void link(int x,int y){ 58 makeroot(x);tree[x].fa=y; 59 } 60 inline int getfa(int x){ 61 access(x);splay(x); 62 while(tree[x].c[0]){x=tree[x].c[0];pushdown(x);} 63 splay(x);return x; 64 } 65 inline int query(int x,int y){ 66 makeroot(x);access(y);splay(y); 67 return tree[y].sum; 68 } 69 inline void change(int x,int val){ 70 makeroot(x);tree[x].val=val;update(x); 71 } 72 int main(){ 73 scanf("%d",&n);for(i=1;i<=n;i++)scanf("%d",&tree[i].val),tree[i].sum=tree[i].val; 74 scanf("%d",&m); 75 while(m--){ 76 scanf("%s%d%d",id,&x,&y); 77 if(id[0]=='e'){ 78 if(getfa(x)!=getfa(y))printf("impossible\n");else printf("%d\n",query(x,y)); 79 }else if(id[0]=='b'){ 80 if(getfa(x)==getfa(y))printf("no\n"); 81 else printf("yes\n"),link(x,y); 82 }else if(id[0]=='p')change(x,y); 83 } 84 return 0; 85 }