淦,竟然卡dinic
给出IASP的模板:
#include<iostream>
#include<algorithm>
#include<cstring>
#include<queue>
using namespace std;
typedef long long ll;
const int max_n=100050;
const int max_m=200050;
const int inf=0x3f3f3f3f;
struct edge {
int to,cap,next;
}E[max_m<<2];
int n,m;
int head[max_n],cnt=1,gap[max_n],last[max_n],d[max_n],que[max_n],ql,qr;
void add(int u,int to,int cap) {
E[++cnt].to=to;E[cnt].cap=cap;
E[cnt].next=head[u];head[u]=cnt;
}int aug(int x,int s,int t,int mi) {
if (x==t) return mi;
int flow=0;
for (int &i=last[x],v=E[i].to;i;i=E[i].next,v=E[i].to) if (d[x]==d[v]+1) {
int tmp=aug(v,s,t,min(mi,E[i].cap));
flow+=tmp,mi-=tmp,E[i].cap-=tmp,E[i^1].cap+=tmp;
if (!mi) return flow;
}
if (!(--gap[d[x]])) d[s]=n+1;
++gap[++d[x]],last[x]=head[x];
return flow;
}
int maxflow(int s,int t) {
fill(gap,gap+n+10,0);fill(d,d+n+10,0);
++gap[d[t]=1];
for (int i=1;i<=n;++i) last[i]=head[i];
que[ql=qr=1]=t;
while (ql<=qr) {
int x=que[ql++];
for (int i=head[x],v=E[i].to;i;i=E[i].next,v=E[i].to) if (!d[v]) ++gap[d[v]=d[x]+1],que[++qr]=v;
}
int ret=aug(s,s,t,inf);
while (d[s]<=n) ret+=aug(s,s,t,inf);
return ret;
}
int xy[max_n][2];
int main(){
int T;scanf("%d",&T);
while (T--){
scanf("%d %d",&n,&m);
fill(head,head+n+5,0);cnt=1;
for (int i=1;i<=n;++i)
scanf("%d %d",&xy[i][0],&xy[i][1]);
for (int i=1,u,v,c;i<=m;++i){
scanf("%d %d %d",&u,&v,&c);
add(u,v,c);add(v,u,c);
}
int s;int t;int cmp1 = inf;int cmp2 = -inf;
for (int i=1;i<=n;++i){
if (xy[i][0]<cmp1){
cmp1=xy[i][0];
s = i;
}
if (xy[i][0]>cmp2){
cmp2=xy[i][0];
t = i;
}
}printf("%d\n",maxflow(s,t));
}
}
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