HoliSPOJ.cpp

#include <cstdio>
#include <iostream>
#include <vector>

using namespace std;

const int N = 100 * 1000 + 10;

vector<int> g[N], w[N];
bool u[N];
int cnt[N];
int n;
long long res;

void dfs(int v)
{
  u[v] = true;
  for (int i = 0; i < g[v].size(); i++)
  {
    int to = g[v][i];
    if (u[to])
      continue;
    dfs(to);
    res += min(cnt[to], n - cnt[to]) * 2ll * w[v][i];
    cnt[v] += cnt[to];
  }
}

void solve(int test)
{
  scanf("%d", &n);
  for (int i = 0; i < n; i++)
  {
    g[i].clear();
    w[i].clear();
    u[i] = false;
    cnt[i] = 1;
  }
  for (int i = 0; i < n - 1; i++)
  {
    int x, y, z;
    scanf("%d%d%d", &x, &y, &z);
    --x;
    --y;
    g[x].push_back(y);
    g[y].push_back(x);
    w[x].push_back(z);
    w[y].push_back(z);
  }
  res = 0;
  dfs(0);
  printf("Case #%d: ", test);
  printf("%lld\n", res);
}

int main()
{
  int t;
  scanf("%d", &t);
  for (int i = 1; i <= t; i++)
    solve(i);

  return 0;
}