1 /**************************************************************
  2     Problem: 3757
  3     User: Tunix
  4     Language: C++
  5     Result: Accepted
  6     Time:17180 ms
  7     Memory:17716 kb
  8 ****************************************************************/
  9  
 10 //BZOJ 3757
 11 #include<cmath>
 12 #include<cstdio>
 13 #include<cstring>
 14 #include<cstdlib>
 15 #include<iostream>
 16 #include<algorithm>
 17 #define rep(i,n) for(int i=0;i<n;++i)
 18 #define F(i,j,n) for(int i=j;i<=n;++i)
 19 #define D(i,j,n) for(int i=j;i>=n;--i)
 20 using namespace std;
 21 void read(int &v){
 22     v=0; int sign=1; char ch=getchar();
 23     while(ch<‘0‘||ch>‘9‘){ if (ch==‘-‘) sign=-1; ch=getchar();}
 24     while(ch>=‘0‘&&ch<=‘9‘){ v=v*10+ch-‘0‘; ch=getchar();}
 25     v*=sign;
 26 }
 27 #define debug
 28 /******************tamplate*********************/
 29 const int N=100010;
 30 int head[N],to[N],next[N],cnt;
 31 void add(int x,int y){
 32     to[++cnt]=y; next[cnt]=head[x]; head[x]=cnt;
 33     to[++cnt]=x; next[cnt]=head[y]; head[y]=cnt;
 34 }
 35 /*******************edge************************/
 36 int n,m,color[N],root;
 37 int B,belong[N],st[N],top,tot,deep[N];
 38 int fa[N][20],bin[25];
 39 void dfs(int x){
 40     int bottom=top;
 41     for(int i=1;i<=16;i++)
 42         if(deep[x]>=bin[i])
 43             fa[x][i]=fa[fa[x][i-1]][i-1];
 44         else break;
 45     for(int i=head[x];i;i=next[i])
 46         if (to[i]!=fa[x][0]){
 47             fa[to[i]][0]=x;
 48             deep[to[i]]=deep[x]+1;
 49             dfs(to[i]);
 50             if (top-bottom>=B){
 51                 ++tot;
 52                 while(top!=bottom)
 53                     belong[st[top--]]=tot;
 54             }
 55         }
 56     st[++top]=x;
 57 }
 58 int LCA(int x,int y){
 59     if (deep[x]<deep[y]) swap(x,y);
 60     int t=deep[x]-deep[y];
 61     for(int i=0;bin[i]<=t;i++)
 62         if (t&bin[i]) x=fa[x][i];
 63     D(i,16,0)
 64         if(fa[x][i]!=fa[y][i])
 65             x=fa[x][i],y=fa[y][i];
 66     if(x==y) return x;
 67     return fa[x][0];
 68 }
 69 /*******************dfs&&LCA********************/
 70 struct ques{
 71     int x,y,a,b,num;
 72     bool operator < (const ques &now)const{
 73         if (belong[x]==belong[now.x]) return belong[y]<belong[now.y];
 74         else return belong[x]<belong[now.x];
 75     }
 76 }Q[N];
 77  
 78 int num[N],ans=0,ANS[N];
 79 bool used[N];
 80 inline void work(int x){
 81     if(!used[x]){
 82         num[color[x]]++;used[x]=1;
 83         if(num[color[x]]==1) ans++;
 84     }
 85     else{
 86         num[color[x]]--;used[x]=0;
 87         if(num[color[x]]==0) ans--;
 88     }
 89 }
 90  
 91 void Xor(int x,int y){
 92     int lca=LCA(x,y);
 93     while(x!=lca) {work(x); x=fa[x][0];}
 94     while(y!=lca) {work(y); y=fa[y][0];}
 95 }
 96  
 97 int main(){
 98     bin[0]=1; F(i,1,20) bin[i]=bin[i-1]<<1;
 99  
100     read(n); read(m);
101     B=sqrt(n);
102     F(i,1,n) read(color[i]);
103     int x,y;
104     F(i,1,n){
105         read(x); read(y);
106         if (x==0) root=y;
107         if (y==0) root=x;
108         add(x,y);
109     }
110     dfs(root);
111     tot++;
112     while(top)belong[st[top--]]=tot;
113  
114     int a,b;
115     F(i,1,m){
116         read(x); read(y); read(a); read(b);
117         Q[i]=(ques){x,y,a,b,i};
118     }
119     sort(Q+1,Q+m+1);
120     //转移的时候不考虑LCA，查答案的时候临时算进来，计算完答案后再把LCA删掉
121     int lca=(LCA(Q[1].x,Q[1].y));
122     Xor(Q[1].x,Q[1].y);
123     work(lca);
124     ANS[Q[1].num]=ans;
125     if (num[Q[1].a]!=0 && num[Q[1].b]!=0 && Q[1].a!=Q[1].b) ANS[Q[1].num]--;
126     work(lca);
127     F(i,2,m){
128         Xor(Q[i-1].x,Q[i].x);
129         Xor(Q[i-1].y,Q[i].y);
130         lca=LCA(Q[i].x,Q[i].y);
131         work(lca);
132         ANS[Q[i].num]=ans;
133         if(num[Q[i].a]!=0 && num[Q[i].b]!=0 && Q[i].a!=Q[i].b) ANS[Q[i].num]--;
134         work(lca);
135     }
136     F(i,1,m) printf("%d\n",ANS[i]);
137     return 0;
138 }