func_code_string: #include <bits/stdc++.h>   using namespace std;   vector<vector<int> > arr;   double ans = 0;   void dfs(int x, int h, int p) {     ans += 1.0 / h;     for (int i = 0; i < arr[x].size(); i++) {       if (arr[x][i] != p) dfs(arr[x][i], h + 1, x);     }   }   int main() {     int n;     cin >> n;     int x, y;     arr.resize(n + 1);     for (int i = 0; i < n - 1; i++) {       cin >> x >> y;       arr[x].push_back(y);       arr[y].push_back(x);     }     dfs(1, 1, -1);     printf( %0.7f , ans);   }   