HDU 4897 Little Devil I

  1 #include <bits/stdc++.h>
  2 using namespace std;
  3 const int maxn = 101010;
  4 struct arc {
  5     int to,next;
  6     arc(int x = 0,int y = -1) {
  7         to = x;
  8         next = y;
  9     }
 10 } e[maxn<<1];
 11 int head[maxn],cnt,tot;
 12 void add(int u,int v) {
 13     e[tot] = arc(v,head[u]);
 14     head[u] = tot++;
 15 }
 16 int dep[maxn],fa[maxn],top[maxn],siz[maxn],son[maxn];
 17 int loc[maxn],sum[maxn<<2],flip[maxn<<2],light[maxn<<2];
 18 void FindHeavyEdge(int u,int father,int depth) {
 19     dep[u] = depth;
 20     fa[u] = father;
 21     siz[u] = 1;
 22     son[u] = -1;
 23     for(int i = head[u]; ~i; i = e[i].next) {
 24         if(e[i].to == father) continue;
 25         FindHeavyEdge(e[i].to,u,depth + 1);
 26         siz[u] += siz[e[i].to];
 27         if(son[u] == -1 || siz[son[u]] < siz[e[i].to])
 28             son[u] = e[i].to;
 29     }
 30 }
 31 void ConnectHeavyEdge(int u,int ancestor){
 32     top[u] = ancestor;
 33     loc[u] = ++cnt;
 34     if(~son[u]) ConnectHeavyEdge(son[u],ancestor);
 35     for(int i = head[u]; ~i; i = e[i].next){
 36         if(e[i].to == fa[u] || e[i].to == son[u]) continue;
 37         ConnectHeavyEdge(e[i].to,e[i].to);
 38     }
 39 }
 40 inline void pushdown(int v,int L,int M,int R){
 41     if(flip[v]){
 42         flip[v<<1] ^= 1;
 43         flip[v<<1|1] ^= 1;
 44         sum[v<<1] = (M - L + 1) - sum[v<<1];
 45         sum[v<<1|1] = (R - M) - sum[v<<1|1];
 46         flip[v] = 0;
 47     }
 48     if(light[v]){
 49         light[v<<1] ^= 1;
 50         light[v<<1|1] ^= 1;
 51         light[v] = 0;
 52     }
 53 }
 54 inline void pushup(int v){
 55     sum[v] = sum[v<<1] + sum[v<<1|1];
 56 }
 57 void update(bool OP,int L,int R,int lt,int rt,int v){
 58     if(lt <= L && rt >= R){
 59         if(OP){
 60             flip[v] ^= 1;
 61             sum[v] = (R - L + 1) - sum[v];
 62         }else light[v] ^= 1;
 63         return;
 64     }
 65     int mid = (L + R)>>1;
 66     pushdown(v,L,mid,R);
 67     if(lt <= mid) update(OP,L,mid,lt,rt,v<<1);
 68     if(rt > mid) update(OP,mid + 1,R,lt,rt,v<<1|1);
 69     pushup(v);
 70 }
 71 int query(bool OP,int L,int R,int lt,int rt,int v){
 72     if(lt <= L && rt >= R) return OP?sum[v]:light[v];
 73     int ret = 0,mid = (L + R)>>1;
 74     pushdown(v,L,mid,R);
 75     if(lt <= mid) ret = query(OP,L,mid,lt,rt,v<<1);
 76     if(rt > mid) ret += query(OP,mid+1,R,lt,rt,v<<1|1);
 77     return ret;
 78 }
 79 void modifyHeavy(int u,int v){
 80     while(top[u] != top[v]){
 81         if(dep[top[u]] < dep[top[v]]) swap(u,v);
 82         update(true,1,cnt,loc[top[u]],loc[u],1);
 83         u = fa[top[u]];
 84     }
 85     if(u == v) return;
 86     if(dep[u] > dep[v]) swap(u,v);
 87     update(true,1,cnt,loc[son[u]],loc[v],1);
 88 }
 89 void modifyLight(int u,int v){
 90     while(top[u] != top[v]){
 91         if(dep[top[u]] < dep[top[v]]) swap(u,v);
 92         update(false,1,cnt,loc[top[u]],loc[u],1);
 93         if(~son[u]) update(true,1,cnt,loc[son[u]],loc[son[u]],1);
 94         update(true,1,cnt,loc[top[u]],loc[top[u]],1);
 95         u = fa[top[u]];
 96     }
 97     if(dep[u] > dep[v]) swap(u,v);
 98     update(false,1,cnt,loc[u],loc[v],1);
 99     if(fa[u]) update(true,1,cnt,loc[u],loc[u],1);
100     if(~son[v]) update(true,1,cnt,loc[son[v]],loc[son[v]],1);
101 }
102 int query(int u,int v,int ret = 0){
103     while(top[u] != top[v]){
104         if(dep[top[u]] < dep[top[v]]) swap(u,v);
105         if(u != top[u]) ret += query(true,1,cnt,loc[son[top[u]]],loc[u],1);
106         ret += query(true,1,cnt,loc[top[u]],loc[top[u]],1)^query(false,1,cnt,loc[fa[top[u]]],loc[fa[top[u]]],1);
107         u = fa[top[u]];
108     }
109     if(u == v) return ret;
110     if(dep[u] > dep[v]) swap(u,v);
111     return ret + query(true,1,cnt,loc[son[u]],loc[v],1);
112 }
113 int main() {
114     int kase,u,v,n,m,op;
115     scanf("%d",&kase);
116     while(kase--){
117         memset(head,-1,sizeof head);
118         memset(sum,0,sizeof sum);
119         memset(flip,0,sizeof flip);
120         memset(light,0,sizeof light);
121         cnt = tot = 0;
122         scanf("%d",&n);
123         for(int i = 1; i < n; ++i){
124             scanf("%d%d",&u,&v);
125             add(u,v);
126             add(v,u);
127         }
128         FindHeavyEdge(1,0,0);
129         ConnectHeavyEdge(1,1);
130         scanf("%d",&m);
131         while(m--){
132             scanf("%d%d%d",&op,&u,&v);
133             switch(op){
134                 case 1:modifyHeavy(u,v);break;
135                 case 2:modifyLight(u,v);break;
136                 case 3:printf("%d\n",query(u,v));break;
137                 default:;
138             }
139         }
140     }
141     return 0;
142 }