最后还是照着题解A了这道题……
#include <bits/stdc++.h>
using namespace std;
int n,m,s,t,edge_sum=1;
int maxflow,mincost;
int dis[5005],head[5005],incf[5005],pre[5005];
bool vis[5005];
struct Edge {int next,to,dis,flow;
}edge[1000005];
inline void addedge(int from,int to,int flow,int dis) {edge[++edge_sum].next=head[from];edge[edge_sum].to=to;edge[edge_sum].dis=dis;edge[edge_sum].flow=flow;head[from]=edge_sum;
}
inline bool spfa() {queue <int> q;memset(dis,0x3f,sizeof(dis));memset(vis,0,sizeof(vis));q.push(s);dis[s]=0;vis[s]=1;incf[s]=1 << 30;while(!q.empty()) {int u=q.front();vis[u]=0;q.pop();for(register int i=head[u];i;i=edge[i].next) {if(!edge[i].flow) continue;int v=edge[i].to;if(dis[v]>dis[u]+edge[i].dis) {dis[v]=dis[u]+edge[i].dis;incf[v]=min(incf[u],edge[i].flow);//更新incfpre[v]=i;if(!vis[v]) vis[v]=1,q.push(v);}}}if(dis[t]==1061109567) return 0;return 1;
}
inline void MCMF() {while(spfa()) {int x=t;maxflow+=incf[t];mincost+=dis[t]*incf[t];int i;while(x!=s) {edge[i].flow-=incf[t];edge[i^1].flow+=incf[t];x=edge[i^1].to;}}
}
signed main() {scanf("%d%d%d%d",&n,&m,&s,&t);for(register int u,v,w,x,i=1;i<=m;++i) {scanf("%d%d%d%d",&u,&v,&w,&x);addedge(u,v,w,x);addedge(v,u,0,-x);}MCMF();printf("%d %d\n",maxflow,mincost);return 0;
