题解说是最小割板子，因为最小割=最大流，于是把最大流板子超过来，然后改了改main函数，但是好像不太对（问题应该是出在main函数上）。

#include <bits/stdc++.h>
#define int long long
using namespace std;

const int INF = 1ll << 28, N = 50010, M = 300010;
int head[N], ver[M], edge[M], nxt[M], d[N], now[M];
int n, m, s, t, tot, maxflow;
queue <int> q;
inline void add(int x, int y, int z) {
	ver[++tot] = y, edge[tot] = z, nxt[tot] = head[x], head[x] = tot;
	ver[++tot] = x, edge[tot] = 0, nxt[tot] = head[y], head[y] = tot;
}

bool bfs() {
	memset(d, 0, sizeof d);
	while (q.size()) q.pop();
	q.push(s); d[s] = 1; now[s] = head[s];
	while (q.size()) {
		int x = q.front(); q.pop();
		//cout << x << "\n";
		for (int i = head[x]; i; i = nxt[i]) 
			if (edge[i] && !d[ver[i]]) {
				q.push(ver[i]);
				now[ver[i]] = head[ver[i]];
				d[ver[i]] = d[x] + 1;
				if (ver[i] == t) return 1;
			}
	}
	return 0;
}

int dinic(int x, int flow) {
	if (x == t) return flow;
	//cout << x << "\n";
	int rest = flow, k, i;
	for (i = now[x]; i && rest; i = nxt[i]) {
		now[x] = i;
		if (edge[i] && d[ver[i]] == d[x] + 1) {
			k = dinic(ver[i], min(rest, edge[i]));
			if (!k) d[ver[i]] = 0;
			edge[i] -= k;
			edge[i ^ 1] += k;
			rest -= k;
		}
	}
	return flow - rest;
}

signed main() {
	cin >> n >> m;
	s = 1+n; t = n; // 不知道设置成啥 
	tot = 1;
	for (int i = 1; i <= m; i++) {
		int x, y, c = 1;
		cin >> x >> y;
		add(x, y + n, INF);
		add(x + n, y, INF);
	}
	for (int i = 1; i <= n; i++) {
		int x;
		cin >> x;
		add(i, i + n, x);
	}
	int flow = 0;
	while (bfs()) 
		while (flow = dinic(s, INF)) maxflow += flow;  // 这两行应该也没问题，蓝书上的
	cout << maxflow << "\n";
	vector <int> ans;
	for (int i = 2; i < n; i++) 
		if (d[i] && !d[i + n]) ans.push_back(i);
	cout << ans.size() << "\n";
	for (int i : ans) cout << i << " ";
}

最大流板子没问题（蓝书代码），问题出在 main() 函数里。（题解太南朝了）