2023/8/11题解

时间限制:

1000MS

内存限制:

65536KB

解题思路

建树 + 模拟 ，复杂在于建树，此处从题目需求可知需要按层建树，所以需要队列模拟，查找比较容易就是普通的深搜

参考代码

#include
using namespace std;
vector<int> v;
vector<int> a;
vector<int> b;
int n,q,num;
int cnt = 1;
const int N = 1e5 + 10;
class node{
  public:
    int val;
    vector<node*> chil;
    node(int num){
        val = num;
    }
};

vector<node*> mp(N,nullptr);

node *root = nullptr;

void build(node *head){
  if(!head){
    return;
  }
  queue<node*> que;
  que.push(head);
  while(!que.empty()){
    int len = que.size();
    for(int k = 0; k < len; ++k){
        head = que.front();
        que.pop();
        int i = cnt - 2;
        int begin = v[i];
        while(i < n - 1 && begin == v[i++]){
            node *t = new node(cnt);
            mp[cnt++] = t;
            head->chil.push_back(t);
        }
        for(node* z : head->chil){
            que.push(z);
        }
    }
  }
 
  
}

int find(node *p){
  if(!p){
    return 1;
  }
  int s = 0;
  for(node *i : p->chil){
    s += find(i);
  }
  return s == 0 ? 1 : s;
}

void debug(node* head){
    if(!head){
        return;
    }
    queue<node*> que;
    que.push(head);
    while(!que.empty()){      
        int len = que.size();
        for(int k = 0; k < len; ++k){
            node* p = que.front();
            que.pop();
            cout << p->val << ' ';
            for(node* i : p->chil){
                que.push(i);
            }
        }
        cout << endl;
    }
    return;
}

int main(){
  root = new node(cnt);
  mp[cnt++] = root;
  cin >> n >> q;
  for(int i = 0; i < n - 1; ++i){
    cin >> num;
    v.push_back(num);
  }
  sort(v.begin(), v.end());
  build(root);
//   debug(root);

  for(int i = 0; i < q; ++i){
    cin >> num;
    a.push_back(num);
  }
  for(int i = 0; i < q; ++i){
    cin >> num;
    b.push_back(num);
  }
  int res = 0;
  
  for(int i = 0 ; i < q; ++i){
    int res_a = find(mp[a[i]]);
    int res_b = find(mp[b[i]]);
    // cout << res_a << ' ' << res_b << endl;
    res ^= res_a * res_b;
  }
  cout << res;
  return 0;
}