Shared code

#include <bits/stdc++.h>  
#define int long long
using namespace std;

const int N = 2e5 + 5;

vector<int> adj[N];
int n, val[N], bit[2 * N], timer = 0, in[N], out[N];

void update(int pos, int val){
  while(pos <= 2 * n + 5){
     bit[pos] += val;
     pos += (pos & -pos);
  }
}

void update(int l, int r, int val){
  update(l, val);
  update(r + 1, -val);
}

int get(int pos){
  int res = 0;
  while(pos > 0){
     res += bit[pos];
     pos -= (pos & -pos);
  }
  return res;
}


void dfs(int node, int par = 0) {

   in[node] = ++timer;

   for(int u : adj[node]) {
      if(u != par) {
         dfs(u, node);
      }
   }
   
   out[node] = timer;
}


int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
  #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
  #endif  

  int x, y, q;
  cin >> n >> q;

  for(int i = 1; i <= n; i++){
     cin >> val[i];
  }

  for(int i = 1; i < n; i++){
    cin >> x >> y;
    adj[x].push_back(y);
    adj[y].push_back(x);
  }
 
  dfs(1);

  for(int i = 1; i <= n; i++){
     update(in[i], out[i], val[i]);
  }


  while(q--){
    int type, s, delta;
    cin >> type;
    if(type == 1){
        cin >> s >> x;
        delta = x - val[s];
        update(in[s], out[s], delta);
    } else{
        cin >> s;
        cout << get(in[s]) << endl;
    }
  }
 return 0;
}