BZOJ 1180: [CROATIAN2009]OTOCI

没什么好说的，就是一道模板题。

只是象征性的留个代码.....

#include<map>#include<cmath>#include<queue>#include<string>#include<cstdio>#include<vector>#include<cstdlib>#include<cstring>#include<algorithm>#define inf 1000000000#define me(a,x) memset(a,x,sizeof a)#define cp(a,x) memcpy(a,x,sizeof a)#define N 30010using namespace std;typedef long long LL;int fa[N],n,m,c[N][2],st[N],w[N],sum[N];bool rev[N];bool Rt(int x){if(c[fa[x]][0]==x || c[fa[x]][1]==x)return 0;return 1;}void pushup(int x){int l=c[x][0],r=c[x][1];sum[x]=sum[l]+sum[r]+w[x];}void pushdown(int x){int l=c[x][0],r=c[x][1];if(rev[x]){rev[x]=0,rev[l]^=1,rev[r]^=1;swap(c[x][0],c[x][1]);}}void rotate(int x){int y=fa[x],z=fa[y],a=c[y][1]==x,b=c[z][1]==y,g=c[x][!a];if(!Rt(y))c[z][b]=x;fa[g]=y,c[y][a]=g;fa[y]=x,c[x][!a]=y;fa[x]=z;pushup(y); pushup(x);}void splay(int x){int top=0,i;for(i=x;!Rt(i);i=fa[i])st[++top]=i;st[++top]=i;for(i=top;i;i--)pushdown(st[i]);while(!Rt(x)){int y=fa[x],z=fa[y],a=c[y][1]==x,b=c[z][1]==y;if(!Rt(y)){if(a==b)rotate(y);else rotate(x);}rotate(x);}}void access(int x){int last=0;while(x){splay(x);c[x][1]=last;pushup(x);last=x,x=fa[x];}}void make_root(int x){access(x); splay(x);rev[x]^=1;}void split(int x,int y){make_root(x);access(y); splay(y);}void link(int x,int y){make_root(x); fa[x]=y;}void cut(int x,int y){split(x,y);fa[x]=c[y][0]=0;}int findrt(int x){access(x); splay(x);while(c[x][0])x=c[x][0];return x;}int main(){int i,x,y,p;char ch[10];scanf("%d",&n);for(i=1;i<=n;i++){scanf("%d",&w[i]);sum[i]=w[i];}scanf("%d",&m);while(m--){scanf("%s%d%d",ch,&x,&y);if(ch[0]=='b'){if(findrt(x)==findrt(y))printf("no\n");else{printf("yes\n"); link(x,y);}}if(ch[0]=='p'){splay(x); w[x]=y; pushup(x);}if(ch[0]=='e'){if(findrt(x)!=findrt(y))printf("impossible\n");else split(x,y),printf("%d\n",sum[y]);}}    return 0;}