1877: [SDOI2009]晨跑 (最小费用最大流)

#include<algorithm>#include<iostream>#include<cstring>#include<cstdlib>#include<cstdio>#define inf 0x7fffffffusing namespace std;inline int read(){    int x=0,f=1;char ch=getchar();    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}    return x*f;}struct edge{int from,to,next,v,c;}e[200001];int n,m,ans1,ans2,cnt=1,S,T,head[1001],from[1001],dis[1001];inline void ins(int u,int v,int w,int c){e[++cnt]=(edge){u,v,head[u],w,c};head[u]=cnt;e[++cnt]=(edge){v,u,head[v],0,-c};head[v]=cnt;}inline bool spfa(){int t=0,w=1,q[10001];bool inq[10001];memset(inq,0,sizeof(inq));for(int i=S;i<=T;i++)dis[i]=inf;dis[S]=0;q[0]=S;inq[S]=1;while(t!=w){int now=q[t++];if(t==T)t=0;for(int i=head[now];i;i=e[i].next)if(e[i].v&&dis[e[i].to]>dis[now]+e[i].c){dis[e[i].to]=dis[now]+e[i].c;from[e[i].to]=i;if(!inq[e[i].to]){inq[e[i].to]=1;q[w++]=e[i].to;if(w==T)w=0;}}inq[now]=0;}if(dis[T]==inf)return 0;return 1;}inline void mcf(){int x=inf;for(int i=from[T];i;i=from[e[i].from])x=min(x,e[i].v);ans1++;for(int i=from[T];i;i=from[e[i].from]){e[i].v-=x;e[i^1].v+=x;ans2+=e[i].c*x;}}int main(){n=read();m=read();S=1;T=n<<1;for(int i=1;i<=m;i++){int a=read(),b=read(),c=read();ins(a+n,b,1,c);}for(int i=2;i<n;i++)ins(i,i+n,1,0);ins(1,S+n,inf,0);ins(n,T,inf,0);while(spfa())mcf();printf("%d %d",ans1,ans2);}