一般图匹配(正向表形式).txt

ACM资料大集合

//一般图最大匹配,正向表形式,复杂度O(n*e)
//返回匹配顶点对数,match返回匹配,未匹配顶点match值为-1
//传入图的顶点数n和正向表list,buf
#define MAXN 100

int aug(int n,int* list,int* buf,int* match,int* v,int now){
	int i,t,ret=0;
	v[now]=1;
	for (i=list[now];i<list[now+1];i++)
		if (!v[t=buf[i]]){
			if (match[t]<0)
				match[now]=t,match[t]=now,ret=1;
			else{
				v[t]=1;
				if (aug(n,list,buf,match,v,match[t]))
					match[now]=t,match[t]=now,ret=1;
				v[t]=0;
			}
			if (ret)
				break;
		}
	v[now]=0;
	return ret;
}

int graph_match(int n,int* list,int* buf,int* match){
	int v[MAXN],i,j;
	for (i=0;i<n;i++)
	v[i]=0,match[i]=-1;
	for (i=0,j=n;i<n&&j>=2;)
		if (match[i]<0&&aug(n,list,buf,match,v,i))
			i=0,j-=2;
		else
			i++;
	for (i=j=0;i<n;i++)
		j+=(match[i]>=0);
	return j/2;
}