| ||||||||||
| Online Judge | Problem Set | Authors | Online Contests | User | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Web Board Home Page F.A.Qs Statistical Charts | Current Contest Past Contests Scheduled Contests Award Contest | |||||||||
Re:第一个最小生成树,也纪念下In Reply To:第一个最小生成树,也纪念下 Posted by:jike0602 at 2009-05-13 15:47:58 #include<iostream>
using namespace std;
int n,p[102],h[102],sum,max1;
struct node{
int x,y,w;
}no[10001];
bool flag[5051][5051];
int cmp(const void *a,const void *b)
{
struct node *a1,*b1;
a1=(struct node *)a;
b1=(struct node *)b;
return a1->w-b1->w;
}
void kruskal(int k);
void makeset();
int findset(int a);
void unionset(int a,int b);
int main()
{
int i,j,a,b,k,c;
while(scanf("%d",&n)!=EOF)
{
sum=n,k=0;
for(i=1;i<=n;i++)
for(j=1;j<=n;j++)
{
scanf("%d",&a);
no[k].x=i;
no[k].y=j;
no[k].w=a;
k++;
}
makeset();
scanf("%d",&c);
memset(flag,false,sizeof(flag));
for(i=0;i<c;i++)
{
scanf("%d%d",&a,&b);
flag[a][b]=true;
a=findset(a);
b=findset(b);
unionset(a,b);
}
if(sum==1)
cout<<0<<endl;
else
{
qsort(no,k,sizeof(no[0]),cmp);
/*for(i=0;i<k;i++)
cout<<no[i].w<<endl;*/
max1=0;
kruskal(k);
}
}
return 0;
}
void makeset()
{
for(int i=1;i<=n;i++)
{
p[i]=i;
h[i]=1;
}
}
int findset(int a)
{
while(a!=p[a])
a=p[a];
return a;
}
void unionset(int a,int b)
{
if(a==b)
return;
if(h[a]==h[b])
{
p[a]=p[b];
h[b]++;
}
else if(h[a]>h[b])
p[b]=p[a];
else
p[a]=p[b];
sum--;
}
void kruskal(int k)
{
int a,b,i=0;
while(1)
{
if(no[i].w!=0)
break;
else
i++;
}
for(;i<k;i++)
{
a=no[i].x,b=no[i].y;
if(flag[a][b])
continue;
a=findset(a);
b=findset(b);
if(a!=b)
{
max1+=no[i].w;
unionset(a,b);
}
if(sum==1)
{
cout<<max1<<endl;
return;
}
}
}
Followed by: Post your reply here: |
All Rights Reserved 2003-2013 Ying Fuchen,Xu Pengcheng,Xie Di
Any problem, Please Contact Administrator