算法1：(建树 + BFS求深度) $O(n)$

//先建树，在宽搜
#include <bits/stdc++.h>
using namespace std;

map<string, int> mp; //名字映射到数字
int id, st[110], old;
string ns[110];
vector<int> g[110];

int get(string s)
{
    if (mp[s])  return mp[s];
    mp[s] = ++id;
    return mp[s];
}

void dfs(int u)
{
    st[u] = 1;
    for (int i = 0; i < g[u].size(); ++ i)
        if (st[g[u][i]] == 0) 
        {
            old ++;
            dfs(g[u][i]);
            old++;
        }
}

int bfs(int u)
{
    //维护出最大层次，在乘以2
    queue<int> q;
    memset(st, 0, sizeof st);
    q.push(u);
    st[u] = 1;

    int deep = 0;
    while (q.size())
    {
        deep++;
        int len = q.size();
        for (int i = 0; i < len; ++ i)
        {
            int t = q.front(); q.pop();
            for (int j = 0; j < g[t].size(); ++ j)
                if (st[g[t][j]] == 0)
                {
                    q.push(g[t][j]);
                    st[g[t][j]] = 1;
                }
        }
    }
    // cout << endl << "shendu: " << deep-1 << endl;
    return (deep-1) * 2 * 10;
}

int main()
{
    int T, n;
    cin >> T;
    while (T--)
    {
        cin >> n;
        for (int i = 0; i < n; ++ i) cin >> ns[i];

        for (int i = 0; i < n; ++ i) g[i].clear();
        mp.clear();
        id = 0;
        mp[ns[n-1]] = ++id; //根节点映射成1
        memset(st, 0, sizeof st);
        old = 0;

        for (int i = 0, a = id; i < n; ++ i)
        {
            int b = get(ns[i]); //获取当前名字映射的数
            g[a].push_back(b);
            a = b;
        }

        dfs(1);
        cout << old * 10 - bfs(1) << endl;
    }
    return 0;
}

算法2：(建树 + dfs求深度) $O(n)$

//先建树，在宽搜
#include <bits/stdc++.h>
using namespace std;

map<string, int> mp; //名字映射到数字
int id, st[110], old, dep;
string ns[110];
vector<int> g[110];

int get(string s)
{
    if (mp[s])  return mp[s];
    mp[s] = ++id;
    return mp[s];
}

void dfs(int u)
{
    st[u] = 1;
    for (int i = 0; i < g[u].size(); ++ i)
        if (st[g[u][i]] == 0) 
        {
            old ++;
            dfs(g[u][i]);
            old++;
        }
}

//维护从根的最深层次
void dfs2(int u, int cur)
{
    st[u] = 1;
    dep = max(dep, cur);
    for (int i = 0; i < g[u].size(); ++ i)
        if (!st[g[u][i]])
            dfs2(g[u][i], cur+1);
    st[u] = 0;
}

int main()
{
    int T, n;
    cin >> T;
    while (T--)
    {
        cin >> n;
        for (int i = 0; i < n; ++ i) cin >> ns[i];

        for (int i = 0; i < n; ++ i) g[i].clear();
        mp.clear();
        id = 0;
        mp[ns[n-1]] = ++id; //根节点映射成1
        memset(st, 0, sizeof st);
        old = dep = 0;

        for (int i = 0, a = id; i < n; ++ i)
        {
            int b = get(ns[i]); //获取当前名字映射的数
            g[a].push_back(b);
            a = b;
        }

        dfs(1);
        memset(st, 0, sizeof st);
        dfs2(1, 1);
        cout << old * 10 - (dep-1) * 20 << endl;
    }
    return 0;
}