深搜写法

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl '\n'
struct Edge
{
    int des, wei;   //目的地 权重
};
int n, ans = 2e9;
vector<Edge> vec[1005];
void dfs(int now, int pre, int sum)
{
    ans = min(ans, sum);
    for (auto i : vec[now])
    {
        if (i.des == pre)
            continue;
        dfs(i.des, now, sum + i.wei);
    }
}
int main()
{
    std::ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> n;
    for (int i = 1; i < n; i++)
    {
        int u, v, w;
        cin >> u >> v >> w;
        vec[u].push_back((Edge){v, w});
        vec[v].push_back((Edge){u, w});
    }
    for (int i = 1; i <= n; i++)
        dfs(i, 0, 0);
    cout << ans << endl;
}