Dinic730ms

尝试了若干次，发现速度依然很慢，去看了其他ac的代码，暂且没能发现问题，可能是当前弧优化的问题（？？），代码如下，还望不吝赐教

#include <bits/stdc++.h>
#define ll long long
#define rint register int 
#define gc getchar
#define inf 200011230000
#define maxm 12000
#define maxn 400
using namespace std;

inline int read(rint ans = 0, rint sgn = ' ', rint ch = gc())
{
    for(; ch < '0' || ch > '9'; sgn = ch, ch = gc());
    for(; ch >='0' && ch <='9';(ans*=10)+=ch-'0', ch = gc());
    return sgn-'-'?ans:-ans;
}

struct Edge{
    ll to,val;
    Edge(ll t=0L,ll v=0L):to(t),val(v){}
}ed[maxm+20];
int he[maxn+20],now[maxn+20],ne[maxm+20],dep[maxn+20],maxint[maxn+20];
int tot=1,n,m,s,t,u,v;
ll w,ans;

void add_edge(int f,int t,ll v){
    ed[++tot]=Edge(t,v);
    ne[tot]=he[f];
    he[f]=tot;
}

bool bfs(int s){
    memcpy(now,he,sizeof(now));
    memcpy(dep,maxint,sizeof(dep));
    queue<int> q;
    q.push(s);
    dep[s]=1;
    while(!q.empty()){
        int tmp=q.front();
        q.pop();
        if(tmp==t) return true;
        for(rint i=he[tmp];i;i=ne[i]){
            if(dep[ed[i].to]==2147483647&&ed[i].val>0){
                dep[ed[i].to]=dep[tmp]+1;
                q.push(ed[i].to);
            }
        }
    }
    return false;
}

ll dfs(int o,ll in){
    if(o==t) return in;
    ll k,out=0;
    for(rint i=now[o];i;i=ne[i]){
        now[o]=i;
        if(dep[ed[i].to]==dep[o]+1&&ed[i].val>0){
            k=dfs(ed[i].to,min(in,ed[i].val));
            ed[i].val-=k;
            ed[i^1].val+=k;
            in-=k;
            out+=k;
            if(ed[i].val==0) dep[ed[i].to]=2147483647;
        }
    }
    return out;
}

int main(){
    cin>>n>>m>>s>>t;
    for(rint i=0;i<maxn;i++) maxint[i]=2147483647;
    for(rint i=1;i<=m;i++){
        u=read();
        v=read();
        w=read();
        add_edge(u,v,w);
        add_edge(v,u,0L);
    }
    while(bfs(s)) ans+=dfs(s,inf);
    cout<<ans;
    return 0;
}