这道C++谁会做啊~谁答出来追加钱！

请问你编程可以做到多少，可以处理输入输出么？

我先发在这

#include<bits/stdc++.h>
using namespace std;
const int MAX_N = 2000100;
const int MAX_M = 2000100;
struct Edge{
    int v,next;
} E1[MAX_M],E2[MAX_M];
int p1[MAX_N],p2[MAX_N],eid1,eid2;
int c1[MAX_N],c2[MAX_N],cid;
bool vis[MAX_N];
void init() {
    memset(p1,-1,sizeof(p1));
    memset(p2,-1,sizeof(p2));
    eid1 = eid2 = 0;
}
void insert1(int u,int v) {
    E1[eid1].v = v;
    E1[eid1].next = p1[u];
    p1[u] = eid1++;
}
void insert2(int u,int v) {
    E2[eid2].v = v;
    E2[eid2].next = p2[u];
    p2[u] = eid2++;
}
int maxlen,point;
void dfs(int u,int step){
    vis[u] = true;
    if(step > maxlen){
        maxlen = step;
        point = u;
    }
    for(int i = p2[u];i != -1;i = E2[i].next){
        if(!vis[E2[i].v]){
            dfs(E2[i].v,step + 1);
        }
    }
}
void zip(int u){
    c2[u] = cid;
    for(int i = p1[u];i != -1;i = E1[i].next){
        if(c1[E1[i].v] == c1[u] && !c2[E1[i].v]) zip(E1[i].v);
    }
}
int diameter(){
    maxlen = -1;
    dfs(1,0);
    memset(vis,0,sizeof(vis));
    maxlen = -1;
    dfs(point,0);
    return maxlen;
}
int main(){
    int n;
    cin >>n;//
    init();
    for(int i = 1;i <= n;i ++) cin >>c1[i];//
    for(int i = 0;i < n - 1;i ++){
        int u,v;
        cin >> u >> v;
        insert1(u,v);
        insert1(v,u);
    }
    for(int i = 1;i <= n;i ++){
        if(!c2[i]){
            cid ++;
            zip(i);
        }
    }
    for(int i = 1;i <= n;i ++){
        for(int j = p1[i];j != -1;j = E1[j].next){
            if(c2[i] != c2[E1[j].v]){
                insert2(c2[i],c2[E1[j].v]);
                insert2(c2[E1[j].v],c2[i]);
            }
        }
    }
    cout << (diameter() + 1) / 2 << endl;
    return 0;
}