2015.10.27 2013---长春

  1 #include<cstdio>
  2 #include<cstring>
  3 #include<iostream>
  4 #include<algorithm>
  5 #include<vector>
  6 using namespace std;
  7 
  8 const int INF = (1<<30)-1;
  9 const int maxn = 400005;
 10 const int MAX_LOG = 20;
 11 
 12 int n,m;
 13 int first[maxn],ecnt;
 14 int fa[MAX_LOG][maxn],dep[maxn];
 15 int dp[maxn],vis[maxn];
 16 int sz[maxn];
 17 
 18 struct Edge{
 19     int u,v,next,w;
 20 };
 21 
 22 struct node{
 23     int type,r;
 24 };
 25 
 26 Edge e[10*maxn],ea[10*maxn];
 27 
 28 void init(){
 29     ecnt  = 0;
 30     memset(first,-1,sizeof(first));
 31 }
 32 
 33 void Add_edge(int u,int v){
 34     e[ecnt].u = u;
 35     e[ecnt].v = v;
 36     e[ecnt].next = first[u];
 37     first[u] = ecnt++;
 38 }
 39 
 40 void Dfs(int p,int pre,int d){
 41     fa[0][p] = pre;
 42     dep[p] = d;
 43     sz[p] = 1;
 44     for(int i = first[p];~i;i = e[i].next){
 45         int v = e[i].v;
 46         if(v == pre) continue;
 47         Dfs(v,p,d+1);
 48         sz[p] += sz[v];
 49     }
 50 }
 51 
 52 void Pre(){
 53     Dfs(1,-1,0);
 54     for(int k = 0;k+1 < MAX_LOG;++k){
 55         for(int v = 1;v <= n;v++){
 56             if(fa[k][v] < 0) fa[k+1][v] = -1;
 57             else fa[k+1][v] = fa[k][fa[k][v]];
 58         }
 59     }
 60 }
 61 
 62 int Lca(int u,int v){
 63     if(dep[u] > dep[v]) swap(u,v);
 64     for(int k = MAX_LOG-1;k >= 0;--k){
 65         if(dep[v]-dep[u] & (1<<k))
 66         v = fa[k][v];
 67     }
 68     if(u == v) return u;
 69     for(int k = MAX_LOG-1;k >= 0;--k){
 70         if(fa[k][u] != fa[k][v]){
 71             u = fa[k][u];
 72             v = fa[k][v];
 73         }
 74     }
 75     return fa[0][u];
 76 }
 77 
 78 int Up(int d,int u){
 79     for(int k = MAX_LOG-1;k >= 0;k--){
 80         if(d & (1<<k)) u = fa[k][u];
 81     }
 82     return u;
 83 }
 84 
 85 node mid(int a,int b,int ab){
 86     node u;
 87     int len = dep[a] + dep[b] - 2*dep[ab];
 88     if(dep[a] >= dep[b]) u = node{1,Up((len-1)/2,a)};
 89     else u = node{2,Up(len/2,b)};
 90     return u;
 91 }
 92 
 93 int solve(int a,int b,int c,int ab,int ac){
 94     node x = mid(a,b,ab);
 95     node y = mid(a,c,ac);
 96     int xx = x.r,yy = y.r;
 97     if(x.type == 1 && y.type == 1){
 98         if(dep[xx] < dep[yy]) swap(xx,yy);//xx shi geng shen de nage
 99         if(Lca(xx,yy) == yy) return sz[xx];
100         return 0;
101     }
102     else if(x.type == 2 && y.type == 2){
103         if(dep[xx] < dep[yy]) swap(xx,yy);
104         if(Lca(xx,yy) == yy) return n-sz[yy];
105         else return n-sz[xx]-sz[yy];
106     }
107     else{
108         if(x.type == 2) swap(xx,yy);// xx shi cong a duan kai shi tiao de
109         if(Lca(xx,yy) == xx) return sz[xx]-sz[yy];
110         else return sz[xx];
111     }
112 }
113         
114 int main(){
115     int T;
116     scanf("%d",&T);
117     while(T--){
118         scanf("%d",&n);
119         init();
120         for(int i = 1;i <= n-1;i++){
121             int u,v;
122             scanf("%d %d",&u,&v);
123             Add_edge(u,v);
124             Add_edge(v,u);
125         }
126         memset(sz,0,sizeof(sz));
127         Pre();
128         scanf("%d",&m);
129         for(int i = 1;i <= m;i++){
130             int a,b,c;
131             scanf("%d %d %d",&a,&b,&c);
132             int lab = Lca(a,b);
133             int lac = Lca(a,c);
134             int lbc = Lca(b,c);
135             printf("%d %d %d\n",solve(a,b,c,lab,lac),solve(b,a,c,lab,lbc),solve(c,a,b,lac,lbc));
136         }
137     }
138     return 0;
139 }