bzoj1877 SDOI2009晨跑 费用流

复习的第三道费用流，拆点以后直接跑。
话说现在省选季也快结束了，弥漫着一股悲伤的气氛（雾）
认识的dalao好像都考挂了（大雾）没考挂的发挥好像也不是很好

#include<cstdio>#include<algorithm>#include<iostream>#include<cstring>#define fo(i,a,b) for(int i=a;i<=b;i++)#define fd(i,a,b) for(int i=a;i>=b;i--)using namespace std;const int N=1e5+5;const int inf=0x7fffffff/3;int S,T;int n,m,k,ans1,ans2;int dis[N],from[N],tot=1,head[N];int q[N];struct node{    int from,to,next,v,c;}e[N<<1];bool vis[N];inline void add(int x,int y,int w,int c){    e[++tot].from=x;    e[tot].to=y;    e[tot].v=w;    e[tot].c=c;    e[tot].next=head[x];    head[x]=tot;}inline void ins(int x,int y,int w,int c){    add(x,y,w,c);    add(y,x,0,-c);}bool spfa(){    int t=0,w=1;    fo(i,S,T)dis[i]=inf;    q[1]=S;    dis[S]=0;    vis[S]=1;    while (t<w)    {        int x=q[++t];        for(int i=head[x];i;i=e[i].next)        {            int v=e[i].to;            if (e[i].v&&e[i].c+dis[x]<dis[v])            {                dis[v]=dis[x]+e[i].c;                from[v]=i;                if (!vis[v])                {                    vis[v]=1;                    q[++w]=v;                }            }        }        vis[x]=0;    }    if (dis[T]==inf)return 0;    else return 1;}inline void mcf(){    int x=inf;    int i=from[T];    while (i)    {        x=min(x,e[i].v);        i=from[e[i].from];    }    ans1++;    i=from[T];    while (i)    {        ans2+=x*e[i].c;        e[i].v-=x;        e[i^1].v+=x;        i=from[e[i].from];    }}int main(){    scanf("%d%d",&n,&m);    S=1,T=n+n;    fo(i,1,m)    {        int x,y,z;        scanf("%d%d%d",&x,&y,&z);        ins(x+n,y,1,z);    }    fo(i,2,n-1)ins(i,i+n,1,0);    ins(1,S+n,inf,0);    ins(n,T,inf,0);    while (spfa())mcf();    printf("%d %d\n",ans1,ans2);    return 0;}