设一个源点， 到所有设备连一条弧， 容量为1， 然后设一个汇点， 所有插座到汇点连弧， 容量为1， 然后
转换器也连一条弧， 容量为1。 最后最大流就是答案。其中注意节点数要开大一些。
#include<cstdio>
#include<queue>
#include<iostream>
#include<vector>
#include<algorithm>
#include<cstring>
#define REP(i, a, b) for(int i = (a); i < (b); i++)
using namespace std;const int MAXN = 512; //注意总的节点数
struct Edge
{int from, to, cap, flow;Edge(int from, int to, int cap, int flow) : from(from), to(to), cap(cap), flow(flow) {}
};
vector<Edge> edges;
vector<int> g[MAXN];
vector<string> name;
int h[MAXN], cur[MAXN], device[MAXN], target[MAXN];
int d[MAXN][MAXN], n, m, k, s, t;
int from[MAXN], to[MAXN]; int ID(string x)
{REP(i, 0, name.size())if(x == name[i])return i;name.push_back(x);return name.size() - 1;
}void AddEdge(int from, int to, int cap)
{edges.push_back(Edge(from, to, cap, 0));edges.push_back(Edge(to, from, 0, 0));g[from].push_back(edges.size() - 2);g[to].push_back(edges.size() - 1);
}bool bfs()
{memset(h, 0, sizeof(h));queue<int> q;q.push(s);h[s] = 1; //不要漏！ while(!q.empty()){int u = q.front(); q.pop();REP(i, 0, g[u].size()){Edge& e = edges[g[u][i]];if(!h[e.to] && e.cap > e.flow){h[e.to] = h[u] + 1;q.push(e.to); } } }return h[t];
}int dfs(int x, int a)
{if(x == t || a == 0) return a;int flow = 0, f;for(int& i = cur[x]; i < g[x].size(); i++){Edge& e = edges[g[x][i]];if(h[x] + 1 == h[e.to] && (f = dfs(e.to, min(a, e.cap - e.flow))) > 0){e.flow += f;edges[g[x][i] ^ 1].flow -= f;flow += f;if((a -= f) == 0) break;}}return flow;
}int solve()
{int ret = 0;while(bfs()) memset(cur, 0, sizeof(cur)), ret += dfs(s, 1e9); return ret;
}int main()
{int T;scanf("%d", &T);while(T--){memset(d, 0, sizeof(d));name.clear();string k1, k2;scanf("%d", &n);REP(i, 0, n){cin >> k1;target[i] = ID(k1);}scanf("%d", &m);REP(i, 0, m){cin >> k1 >> k2;device[i] = ID(k2);}scanf("%d", &k);REP(i, 0, k){cin >> k1 >> k2;from[i] = ID(k1);to[i] = ID(k2);}int V = name.size();s = V, t = V + 1;edges.clear();REP(i, 0, V + 2) g[i].clear();REP(i, 0, m) AddEdge(s, device[i], 1);REP(i, 0, n) AddEdge(target[i], t, 1);REP(i, 0, k) AddEdge(from[i], to[i], 1e9); printf("%d\n", m - solve());if(T) puts("");}return 0;
}