建图方式：
S->同意 ,反对->T

对于每一对好友连容量为1的边

#include <bits/stdc++.h>
using namespace std;
const int inf = 1e9;
const int MAXN = 3e2+7;
const int MAXM = 2e5+7;
int n, m, s, t, dep[MAXN], maxflow;
struct Edge {int v, w, next;
} G[MAXM];
int tot = 1, head[MAXN], cur[MAXN];
inline void add(int u, int v, int w) {G[++tot].v=v, G[tot].w=w, G[tot].next=head[u];head[u]=tot;
}bool bfs(int s, int t) {memset(dep, 0x7f, sizeof dep);memcpy(cur+1, head+1, n*4+8);queue<int>q;while(!q.empty()) q.pop();dep[s] = 0;q.push(s);while(!q.empty()) {int u = q.front();q.pop();for(int i = head[u]; i; i = G[i].next) {int v = G[i].v, w = G[i].w;if (dep[v] > inf && w) {dep[v] = dep[u] + 1;if (v == t) return 1;q.push(v);}}}return dep[t] < inf;
}int dfs(int u, int t, int limit) {if (u == t || !limit) return limit;int flow = 0, f;for(int i = cur[u]; i; i = G[i].next) {cur[u] = i;int v = G[i].v, w = G[i].w;if (dep[v] == dep[u] + 1 && (f = dfs(v, t, min(w, limit)))) {flow += f;limit -= f;G[i].w -= f;G[i^1].w += f;if (!limit) break;}}return flow;
}void dinic(int s, int t) {while(bfs(s, t)) maxflow += dfs(s, t, inf);
}int main(void) {// memset(head, -1, sizeof head);scanf("%d%d", &n, &m);for(int i = 1; i <= n; ++i) {scanf("%d", &s);if (s) add(n+1, i, 1), add(i, n+1, 0);else add(i, n+2, 1), add(n+2, i, 0);}for(int i = 1; i <= m; ++i) {int u, v;scanf("%d%d", &u, &v);add(u, v, 1), add(v, u, 1);
//      add(u, v, 0), add(v, u, 0);//加不加都行，因为不会退流}dinic(n+1, n+2);printf("%d", maxflow);return 0;
}