POJ1966(Cable TV Network)

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <stack>
#include <cctype>
#include <queue>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <climits>
#define lson root<<1,l,mid
#define rson root<<1|1,mid+1,r
#define fi first
#define se second
#define ping(x,y) ((x-y)*(x-y))
#define mst(x,y) memset(x,y,sizeof(x))
#define mcp(x,y) memcpy(x,y,sizeof(y))
#define Min(x,y) (x<y?x:y)
#define Max(x,y) (x>y?x:y)
using namespace std;
#define gamma 0.5772156649015328606065120
#define MOD 1000000007
#define inf 0x3f3f3f3f
#define N 10005
#define maxn 1000050
typedef long long LL;
typedef pair<int,int> PII;

int n,m;
int lel[305],head[305];
struct Node{
    int to,next,v;
    Node(){}
    Node(int a,int b,int c):to(a),next(b),v(c){}
}node[N];int hcnt;

inline void init(){
    hcnt=0;
    mst(head,-1);
}
int bfs(int s,int t){
    int i;
    queue<int>q;
    mst(lel,-1);
    lel[s]=0;
    q.push(s);
    while(!q.empty()){
        int x=q.front();q.pop();
        if(x==t)return 1;
        for(i=head[x];~i;i=node[i].next){
            int e=node[i].to;
            if(lel[e]==-1&&node[i].v){
                lel[e]=lel[x]+1;
                q.push(e);
            }
        }
    }
    return 0;
}

inline void init_flow(){
    for(int i=0;i<hcnt;i+=2){
        node[i].v+=node[i^1].v;
        node[i^1].v=0;
    }
}

int dfs(int s,int t,int v){
    if(s==t) return v;
    int flow=0;
    for(int i=head[s];~i;i=node[i].next){
        int e=node[i].to,f=node[i].v;
        if(lel[e]==lel[s]+1&&f){
            int al=Min(v-flow,f);
            al=dfs(e,t,al);
            node[i].v-=al;
            node[i^1].v+=al;
            flow+=al;
            if(flow==v)return flow;
        }
    }
    return flow;
}

int Dinic(int s,int t){
    int res=0;
    while(bfs(s,t))res+=dfs(s,t,inf);
    return res;
}

inline void add(int x,int y,int v){
    node[hcnt]=Node(y,head[x],v);
    head[x]=hcnt++;
    node[hcnt]=Node(x,head[y],0);
    head[y]=hcnt++;
}

int main(){
    int i,j,group,Case=0,x,y;
    while(scanf("%d%d",&n,&m)!=EOF){
        init();
        for(i=0;i<n;++i)add(i,i+n,1);
        while(m--){
            scanf(" (%d,%d)",&x,&y);
            add(x+n,y,inf);
            add(y+n,x,inf);
        }
        int ans=inf;
        for(i=1;i<n;++i){
            ans=min(ans,Dinic(0+n,i));
            init_flow();
        }
        if(ans==inf)ans=n;
        printf("%d\n",ans);
    }
    return 0;
}