Submission #2582139

---

Source Code Expand

#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007

int n;
vector< vector<int> > v;
vector<long long> f, g;
vector<bool> used;

long long dfs(int p){
  g[p] = 1;
  f[p] = 1;
  used[p] = true;
  for (int i = 0; i < v[p].size(); i++) {
    if (used[v[p][i]]) continue;
    dfs(v[p][i]);
    g[p] *= f[v[p][i]];
    f[p] *= g[v[p][i]];
    f[p] %= mod; g[p] %= mod;
  }
  f[p] += g[p];
  f[p] %= mod;
  return f[p];
}

int main(){
  cin >> n;
  v.resize(n+1);
  f.resize(n+1);
  g.resize(n+1);
  used.resize(n+1, false);
  for (int i = 0; i < n-1; i++) {
    int a, b; cin >> a >> b;
    v[a].push_back(b);
    v[b].push_back(a);
  }
  cout << dfs(1) << endl;
  return 0;
}

Submission Info

Judge Result