Submission #1239750

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Source Code Expand

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cmath>
using namespace std;

#define int long long
typedef pair<int, int> P;
#define rep(i, n) for (int i=0; i<(n); i++)
#define all(c) (c).begin(), (c).end()
#define uniq(c) c.erase(unique(all(c)), (c).end())
#define _1 first
#define _2 second
#define pb push_back
#define INF 1145141919
#define MOD 1000000007

int N;
vector<P> G[100000];

long long X;
map<long long, int> C;
long long ans;

void dfs(int x, int p, int d, bool f=true) {
  if (C.find(d^X) != C.end()) ans += C[d^X];
  C[d]++;
  for (P &pp : G[x]) {
    int t = pp._1;
    if (t == p) continue;
    dfs(t, x, d^pp._2);
  }
}
signed main() {
  ios::sync_with_stdio(false); cin.tie(0);
  cin >> N >> X;
  for (int i=0; i<N-1; i++) {
    int u, v, l;
    cin >> u >> v >> l;
    G[u-1].push_back(P(v-1, l));
    G[v-1].push_back(P(u-1, l));
  }
  dfs(0, -1, 0, false);
  cout << ans << "\n";
  return 0;
}

Submission Info

Judge Result