[Codevs] 1228 苹果树

  1 #include<cstdio>
  2 #include<iostream>
  3 #define mid (L+R)/2
  4 #define lc (rt<<1)
  5 #define rc (rt<<1|1)
  6 #define maxn 1000000
  7 using namespace std;
  8 
  9 int dfn[maxn],TIM = 1,dfn_t[maxn],n,a,b,c,m,pos,tl[maxn];
 10 char ctr;
 11 
 12 struct edge{
 13     int from,v;
 14 }e[maxn];
 15 
 16 struct node{
 17     int sum;
 18 }Tree[maxn];
 19 
 20 void maintain(int rt){
 21     Tree[rt].sum = Tree[lc].sum+Tree[rc].sum;
 22 }
 23 
 24 void build(int rt,int L,int R){
 25     if(L == R) Tree[rt].sum = 1;
 26     else{
 27         build(lc,L,mid);
 28         build(rc,mid+1,R);
 29         
 30         maintain(rt);
 31     }
 32 }
 33 
 34 void add(int rt,int L,int R,int pos){
 35     if(L == R) Tree[rt].sum ^= 1;
 36     else{
 37         if(pos <= mid) add(lc,L,mid,pos);
 38         else add(rc,mid+1,R,pos);
 39         
 40         maintain(rt);
 41     }
 42 }
 43 
 44 int query(int rt,int L,int R,int qL,int qR){
 45     if(qL <= L && R <= qR) return Tree[rt].sum;
 46     else{
 47         int ans = 0;
 48         if(qL <= mid) ans += query(lc,L,mid,qL,qR);
 49         if(qR > mid) ans += query(rc,mid+1,R,qL,qR);
 50         return ans;
 51     }
 52 }
 53 
 54 void PRINT(int rt,int L,int R){
 55     if(L == R) printf("%d ",Tree[rt].sum);
 56     else{
 57         PRINT(lc,L,mid);
 58         PRINT(rc,mid+1,R);
 59     }
 60 }
 61 
 62 int tot,first[maxn];
 63 void insert(int u,int v){
 64     tot++;
 65     e[tot].from = first[u];
 66     e[tot].v = v;
 67     first[u] = tot;
 68 }
 69 
 70 void dfs(int now,int pre){
 71     dfn[now] = TIM++;
 72     tl[dfn[now]] = now;
 73 //    Tree[dfn[now]].sum = 1;
 74     for(int i = first[now];i;i = e[i].from){
 75         int v = e[i].v;
 76         if(v != pre){
 77             dfs(v,now);
 78         }
 79     }dfn_t[now] = TIM++;
 80     tl[dfn_t[now]] = now; 
 81 }
 82 
 83 int main(){
 84     scanf("%d",&n);
 85     for(int i = 1;i < n;i++){
 86         scanf("%d%d",&a,&b);
 87         insert(a,b);
 88         insert(b,a);
 89     }
 90     
 91     
 92     dfs(1,-1);
 93     TIM--;
 94 //    build(1,1,TIM-1);
 95     for(int i = 1;i <= n;i++){
 96         add(1,1,TIM,dfn[i]);
 97     }
 98     
 99     scanf("%d",&m);
100     for(int i = 1;i <= m;i++){
101         cin >> ctr >> pos;
102         if(ctr == ‘C‘) add(1,1,TIM,dfn[pos]);
103         else printf("%d\n",query(1,1,TIM,dfn[pos],dfn_t[pos]));
104 //        PRINT(1,1,TIM-1);cout << endl;
105     }
106     
107 //    for(int i = 1;i <= n;i++){
108 //        printf("%d ",dfn[i]);
109 //    }cout << "##";
110     
111 //    for(int i = 1;i <= TIM;i++) printf("%d ",tl[i]);
112     
113     return 0;
114 }