BZOJ 1180 / 2843 LCT模板题_双倍经验

一大早上到机房想先拍一下模板，热热身.

结果....对照着染色敲的 LCT 竟然死活也调不过去（你说我抄都能抄错）

干脆自己重新敲了一遍，10min就敲完了.......

还是要相信自己

Code:

#include <bits/stdc++.h>
#define setIO(s) freopen(s".in","r",stdin)
using namespace std;
  #define maxn 40000
struct LCT
{
    #define lson ch[x][0]
    #define rson ch[x][1]
    int tag[maxn],val[maxn],sumv[maxn],ch[maxn][2],f[maxn],sta[maxn];
    int isRoot(int x)
    {
        return !(ch[f[x]][1] == x || ch[f[x]][0] == x);
    }
    int get(int x)
    {
        return ch[f[x]][1] == x;
    }
    void mark(int x)
    {
        if(!x) return ;
        swap(lson, rson), tag[x] ^= 1;
    }
    void pushdown(int x)
    {
        if(!x) return ;
        if(tag[x])
        {
            mark(lson), mark(rson), tag[x] ^=1 ;
        }
    }
    void pushup(int x)
    {
        sumv[x] = sumv[lson] + sumv[rson] + val[x];
    }
    void rotate(int x)
    {
        int old = f[x], fold = f[old], which = get(x);
        if(!isRoot(old)) ch[fold][ch[fold][1] == old] = x;
        ch[old][which] = ch[x][which ^ 1], f[ch[old][which]] = old;
        ch[x][which ^ 1 ] = old, f[old] = x, f[x] = fold;
        pushup(old),pushup(x);
    }
    void splay(int x)
    {
        int u = x, v = 0;
        sta[++v] = u;
        while(!isRoot(u)) sta[++v] = f[u], u = f[u];
        while(v) pushdown(sta[v--]);
        u = f[u];
        for(int fa; (fa = f[x]) != u; rotate(x))
            if(f[fa] != u) rotate(get(fa) == get(x) ? fa: x);
    }
    void Access(int x)
    {
        for(int y = 0; x ; y = x,x = f[x])
        {
            splay(x), rson = y, pushup(x);
        }
    }
    void makeRoot(int x)
    {
        Access(x), splay(x), mark(x);
    }
    void link(int a,int b)
    {
        makeRoot(a), f[a] = b;
    }
    void split(int a,int b)
    {
        makeRoot(a), Access(b), splay(b);
    }
}T;
struct Union_Find
{
    int p[maxn];
    void init()
    {
        for(int i = 0;i < maxn ;++i) p[i] = i;
    }
    int find(int x)
    {
        return p[x] == x ? x : p[x] = find(p[x]);
    }
    int merge(int a,int b)
    {
        int x = find(a), y = find(b);
        if(x == y) return 0;
        p[x] = y;
        return 1;
    }
}U;
char str[20];
int main()
{
    // setIO("input");
    U.init();
    int n;
    scanf("%d",&n);
    for(int i = 1;i <= n; ++i) scanf("%d",&T.val[i]), T.sumv[i] = T.val[i];
    int q,a,b,c;
    scanf("%d",&q);
    while(q --)
    {
        scanf("%s",str);
        if(str[0] == 'b')
        {
            scanf("%d%d",&a,&b);
            if(!U.merge(a,b))
                printf("no\n");
            else
            {
                T.link(a, b);
                printf("yes\n");
            }
        }
        if(str[0] == 'p' )
        {
            scanf("%d%d",&a,&b);
            T.makeRoot(a),T.val[a] = b, T.pushup(a);
        }
        if(str[0] == 'e')
        {
            scanf("%d%d",&a,&b);
            if(U.find(a) == U.find(b))
            {
                T.split(a,b);
                printf("%d\n",T.sumv[b]);
            }else printf("impossible\n");
        }
    }
    return 0;
}