求助dinic是否写假

已经过题，但是时间比其他选手的劣很多。

希望能帮忙看一下，谢谢。

参考提交（别人的，总共59ms）：https://www.luogu.com.cn/record/67846830

我的代码（总共279ms）：

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

#define fo(i,a,b) for(int i=a;i<=b;++i)
#define go(i,a) for(int i=cur[a];i;i=edge[i].nxt)
#define mem(a,b) memset(a,b,sizeof(a))
#define ll long long

const int N = 5005;
const int INF = 2e9;

int n, m;
struct nod {
    int y, nxt;
    int c;
}edge[N<<2];
int el = 1;
int Edgehead[N];
int dis[205];
int cur[205];
int S, T;
int q[205], head, tail;

void add (int x, int y, ll c) {
    el++;
    edge[el].y = y, edge[el].c = c, edge[el].nxt = Edgehead[x], Edgehead[x] = el;
    return;
}

void ins (int x, int y, ll c) {
    add (x, y, c);
    add (y, x, 0ll);
    return;
}

bool bfs () {
    mem (dis, -1);
    dis[S] = 0;
    q[head = 1] = S, tail = 2;
    while (head < tail) {
        int x = q[head++];
        cur[x] = 0;
        for (int i = Edgehead[x]; i; i = edge[i].nxt) {
            int y = edge[i].y;
            if (edge[i].c && dis[y] == -1) {
                if (!cur[x]) cur[x] = i;
                dis[y] = dis[x] + 1;
                q[tail++] = y;
            }
        }
    }
    return dis[T] != -1;
}

int dfs (int k, int flow) {
    if (k==T || !flow) return flow;
    int have = 0;
    go (i,k) {
        int y=edge[i].y;
        if (dis[y] == dis[k]+1 && edge[i].c) {
            int back = dfs (y, min(flow-have, edge[i].c));
            have += back;
            edge[i].c -= back;
            edge[i^1].c += back;
            if (have == flow)return flow;
        }
        cur[k] = edge[i].nxt;
    }
    dis[k] = -1;
    return have;
}

int main () {
//  freopen ("3376.in", "r", stdin);
    mem (Edgehead, 0);
    scanf ("%d %d %d %d", &n, &m, &S, &T);
    fo (i,1,m) {
        int x, y, c;
        scanf ("%d %d %d", &x, &y, &c);
        ins (x, y, c);
    }
    ll ans = 0;
    while (bfs ()) {
        ans += dfs (S, INF);
    }
    printf ("%lld\n", ans);
    return 0;
}