Language: C++

#define INF 1<<30
#define LINF 1LL60

struct edge {
	int to; // ?????????
	int cap; // ??????
	int rev; // ??????
	edge() {}
	edge(int to, int cap, int rev) :to(to), cap(cap), rev(rev) {}
};

vector<vector<edge>> G; // ??°???????????£??\???????????¨???
vector<int> used; // DFS??§?????§???????????????????????°

// from??????to??????????????????cap???????????°?????????????????????
void add_edge(int from, int to, int cap) {
	G[from].push_back(edge(to, cap, G[to].size()));
	G[to].push_back(edge(from, cap, G[to].size() - 1));
}

// ?¢?????????????DFS??§??¢???
int dfs(int v, int t, int f) {
	if (v == t) return f;
	used[v] = true;
	for (int i = 0; i < G[v].size(); i++) {
		edge &e = G[v][i];
		if (!used[e.to] && e.cap > 0) {
			int d = dfs(e.to, t, min(f, e.cap));
			if (d > 0) {
				e.cap -= d;
				G[e.to][e.rev].cap += d;
				return d;
			}
		}
	}
	return 0;
}

// s??????t???????????§???????±???????
int max_flow(int s, int t) {
	int flow = 0;
	for (;;) {
		fill(used.begin(), used.end(), 0);
		int f = dfs(s, t, INF);
		if (f == 0) return flow;
		flow += f;
	}
}


/* use example */
int main() {
	cin.tie(0); ios::sync_with_stdio(false);
	int V, E; cin >> V >> E;
	G.resize(V); used.resize(V);
	for (int i = 0; i < E;i++) {
		int s, t, c; cin >> s >> t >> c;
		add_edge(s, t, c);
	}
	cout << max_flow(0, V - 1) << endl;
	return 0;
}

Compiler output:
a.cc:12:1: error: 'vector' does not name a type
   12 | vector<vector<edge>> G; // ??°???????????£??\???????????¨???
      | ^~~~~~
a.cc:13:1: error: 'vector' does not name a type
   13 | vector<int> used; // DFS??§?????§???????????????????????°
      | ^~~~~~
a.cc: In function 'void add_edge(int, int, int)':
a.cc:17:9: error: 'G' was not declared in this scope
   17 |         G[from].push_back(edge(to, cap, G[to].size()));
      |         ^
a.cc: In function 'int dfs(int, int, int)':
a.cc:24:9: error: 'used' was not declared in this scope
   24 |         used[v] = true;
      |         ^~~~
a.cc:25:29: error: 'G' was not declared in this scope
   25 |         for (int i = 0; i < G[v].size(); i++) {
      |                             ^
a.cc:28:46: error: 'min' was not declared in this scope
   28 |                         int d = dfs(e.to, t, min(f, e.cap));
      |                                              ^~~
a.cc: In function 'int max_flow(int, int)':
a.cc:43:22: error: 'used' was not declared in this scope
   43 |                 fill(used.begin(), used.end(), 0);
      |                      ^~~~
a.cc:43:17: error: 'fill' was not declared in this scope
   43 |                 fill(used.begin(), used.end(), 0);
      |                 ^~~~
a.cc: In function 'int main()':
a.cc:53:9: error: 'cin' was not declared in this scope
   53 |         cin.tie(0); ios::sync_with_stdio(false);
      |         ^~~
a.cc:53:21: error: 'ios' has not been declared
   53 |         cin.tie(0); ios::sync_with_stdio(false);
      |                     ^~~
a.cc:55:9: error: 'G' was not declared in this scope
   55 |         G.resize(V); used.resize(V);
      |         ^
a.cc:55:22: error: 'used' was not declared in this scope
   55 |         G.resize(V); used.resize(V);
      |                      ^~~~
a.cc:60:9: error: 'cout' was not declared in this scope
   60 |         cout << max_flow(0, V - 1) << endl;
      |         ^~~~
a.cc:60:39: error: 'endl' was not declared in this scope
   60 |         cout << max_flow(0, V - 1) << endl;
      |                                       ^~~~