记录编号	164722	评测结果	AAAAAAAAAA
题目名称	[CF 343E]供水泵站	最终得分	100
用户昵称	cstdio	是否通过	通过
代码语言	C++	运行时间	0.038 s
提交时间	2015-06-05 09:56:59	内存使用	0.32 MiB

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<vector>
#include<queue>
using namespace std;
const int SIZEN=210,INF=0x7fffffff/2;
class EDGE{
public:
	int from,to,cap,flow;
};
vector<EDGE> edges;
vector<int> c[SIZEN];
int S,T;
bool visit[SIZEN]={0};
int depth[SIZEN]={0};
int cur[SIZEN]={0};
void clear_graph(void){
	edges.clear();
	for(int i=0;i<SIZEN;i++) c[i].clear();
}
void clear_flow(void){
	for(int i=0;i<edges.size();i++) edges[i].flow=0;
}
void addedge_2(int from,int to,int cap){//加双向边
	EDGE temp;
	temp.from=from,temp.to=to,temp.cap=cap,temp.flow=0;
	edges.push_back(temp);
	temp.from=to,temp.to=from,temp.cap=cap,temp.flow=0;
	edges.push_back(temp);
	int tot=edges.size()-2;
	c[from].push_back(tot);
	c[to].push_back(tot+1);
}
bool BFS(void){
	memset(visit,0,sizeof(visit));
	memset(depth,-1,sizeof(depth));
	queue<int> Q;
	Q.push(S);visit[S]=true;depth[S]=0;
	while(!Q.empty()){
		int x=Q.front();Q.pop();
		for(int i=0;i<c[x].size();i++){
			EDGE &now=edges[c[x][i]];
			if(!visit[now.to]&&now.cap>now.flow){
				visit[now.to]=true;
				depth[now.to]=depth[x]+1;
				Q.push(now.to);
			}
		}
	}
	return visit[T];
}
int DFS(int x,int a){
	if(x==T||!a) return a;
	int flow=0,cf=0;
	for(int i=cur[x];i<c[x].size();i++){
		cur[x]=i;
		EDGE &now=edges[c[x][i]];
		if(depth[x]+1==depth[now.to]){
			cf=DFS(now.to,min(a,now.cap-now.flow));
			if(cf){
				flow+=cf;
				a-=cf;
				now.flow+=cf,edges[c[x][i]^1].flow-=cf;
			}
			if(!a) break;
		}
	}
	if(!flow) depth[x]=-1;
	return flow;
}
int Dinic(void){
	int flow=0;
	while(BFS()){
		memset(cur,0,sizeof(cur));
		flow+=DFS(S,INF);
	}
	return flow;
}
int N,M;
int fa[SIZEN],falen[SIZEN];
int now;
void find_min(int x,int fa){
	for(int i=0;i<c[x].size();i++){
		EDGE &e=edges[c[x][i]];
		if(e.to!=fa&&e.cap!=-1){
			if(now==-1||e.cap<edges[now].cap) now=c[x][i];
			find_min(e.to,x);
		}
	}
}
void Solve(int x){
	now=-1;
	find_min(x,0);
	if(now==-1){
		printf("%d ",x);
		return;
	}
	edges[now].cap=edges[now^1].cap=-1;
	int p=now;
	Solve(edges[p].from);
	Solve(edges[p].to);
}
int ans=0;
void build_tree(void){//建树
	for(int i=1;i<=N;i++) fa[i]=1;
	for(int i=2;i<=N;i++){
		clear_flow();
		S=i,T=fa[i];
		falen[i]=Dinic();
		BFS();
		for(int j=i+1;j<=N;j++)
			if(visit[j]&&fa[j]==fa[i]) fa[j]=i;
	}
	clear_graph();
	for(int i=2;i<=N;i++)
		addedge_2(i,fa[i],falen[i]),ans+=falen[i];
}
void answer(void){
	printf("%d\n",ans);
	//Solve(1);
	//printf("\n");
}
void init(void){
	scanf("%d%d",&N,&M);
	int a,b,w;
	for(int i=1;i<=M;i++){
		scanf("%d%d%d",&a,&b,&w);
		addedge_2(a,b,w);
	}
}
int main(){
	freopen("pumpingstations.in","r",stdin);
	freopen("pumpingstations.out","w",stdout);
	init();
	build_tree();
	answer();
	return 0;
}