未完成

#include <cstdio>
#include <queue>
#define N 30005
#define inf 0x3f3f3f3f
using namespace std;
bool vis[N];
int n,m,c,S,T,cnt=1,to[N<<1],fa[N],DIS[N],came[N],flow[N<<1],val[N<<1],head[N],nextt[N<<1];
void ins(int u,int v,int f,int w)
{
    nextt[++cnt]=head[u];to[cnt]=v;flow[cnt]=f;val[cnt]=w;head[u]=cnt;
    nextt[++cnt]=head[v];to[cnt]=u;flow[cnt]=0;val[cnt]=-w;head[v]=cnt;
}
inline int min(int a,int b) {return a>b?b:a;}
bool spfa()
{
    for(int i=S;i<=T;++i) DIS[i]=inf,came[i]=inf,vis[i]=false;
    DIS[S]=0;
    queue<int>q;
    q.push(S);
    for(int u;!q.empty();)
    {
        u=q.front();
        q.pop();
        vis[u]=false;
        for(int i=head[u];i;i=nextt[i])
        {
            int v=to[i];
            if(DIS[v]>DIS[u]+val[i]&&flow[i])
            {
                DIS[v]=DIS[u]+val[i];
                fa[v]=i;
                came[v]=min(came[u],flow[i]);
                if(!vis[v]) {vis[v]=true;q.push(v);}
            }
        }
    }
    return DIS[T]!=inf;
}
int main(int argc,char *argv[])
{
    scanf("%d%d%d",&n,&m,&c);
    S=0,T=n+1;
    int ans=0,left=n;
    for(int s,t,v;m--;)
    {
        scanf("%d%d%d",&s,&t,&v);
        ins(s,t,1,v);
        ins(S,s,inf,inf-1);
        ins(t,T,inf,inf-1);
    }
    while(spfa())
    {
        int t=came[T];
        left-=t;
        for(int i=T;i!=S&&i;i=to[fa[i]^1])
        {
            flow[fa[i]]-=t;
            flow[fa[i]^1]+=t;
        }
        ans+=t*DIS[T];
    }
    printf("%d\n",ans+left*c);
    return 0;
}