POJ 1251 解題報告 （最小生成樹模板，kruskal 和prim）

板子題

Prim

#include<iostream>
#include<queue>
#include<cstring>
#include<string>
#include<sstream>
#include<map>
#include<vector>
#include<cstdio>
#include<iostream>
#include<cmath>
#include<algorithm>
#include<cstdlib>
#include<stack>
#include<ctime>
using namespace std; 
#define rep(i,aa,bb) for(register int i=aa;i<=bb;i++)
#define rrep(i,aa,bb) for(register int i=aa;i>=bb;i--)
#define mset(var,val)	 memset(var,val,sizeof(var))
#define LL long long 
#define eps 0.000001
#define inf 0x7f7f7f7f
#define llinf 1e18
#define exp 0.000001
#define pai 3.141592654
#define random(x)   rand()%(x)
#define lowbit(x)   x&(-x)
inline int read()
{
	int x=0,y=1;char a=getchar();while ( a>'9' || a<'0'){if ( a=='-')y=-1;a=getchar();}
	while ( a>='0' && a<='9' ){	x=(x<<3)+(x<<1)+a-'0'; a=getchar();}return x*y;
}
#define N 200
int e[N][N],dis[N];
bool vis[N];
int n;  
void prim(){
	int minx ,v; 
	rep(i,0,n-1)	dis[i]=e[0][i],vis[i] = 0; 
	rep(i,1,n){
		minx = inf; 
		rep(j,0,n-1){
			if( !vis[j] && minx > dis[j])
				v = j , minx = dis[j];			

		}
		vis[ v ] = true; 		
		rep(j,0,n-1){
			if ( !vis[j] && dis[j] > e[v][j] )
				dis[j] = e[v][j];
		}		
	}
	int suma = 0 ; 
	rep(i,1,n-1)	suma += dis[i];
	printf("%d\n",suma);
}
int main()
{
//	freopen("1.txt","r",stdin);
	srand((int)time(0));
//	std::ios::sync_with_stdio(false);
	while ( scanf("%d",&n) && n ){
		mset(e,0x3f); 
		rep(i,0,n) e[i][i] = 0; 
		char s[ 5 ],en[5];int w,m; 
		rep(i,1,n-1){
			scanf("%s%d",s,&m);
			rep(j,1,m){
				scanf("%s%d", en, &w);
                e[s[0]-'A'][en[0]-'A'] = e[en[0]-'A'][s[0]-'A'] = w;
			}
		}
		prim();
	}
	return 0;
}

Kruskal

#include<iostream>
#include<queue>
#include<cstring>
#include<string>
#include<sstream>
#include<map>
#include<vector>
#include<cstdio>
#include<iostream>
#include<cmath>
#include<algorithm>
#include<cstdlib>
#include<stack>
#include<ctime>
using namespace std; 
#define rep(i,aa,bb) for(register int i=aa;i<=bb;i++)
#define rrep(i,aa,bb) for(register int i=aa;i>=bb;i--)
#define mset(var,val)	 memset(var,val,sizeof(var))
#define LL long long 
#define eps 0.000001
#define inf 0x7f7f7f7f
#define llinf 1e18
#define exp 0.000001
#define pai 3.141592654
#define random(x)   rand()%(x)
#define lowbit(x)   x&(-x)
inline int read()
{
	int x=0,y=1;char a=getchar();while ( a>'9' || a<'0'){if ( a=='-')y=-1;a=getchar();}
	while ( a>='0' && a<='9' ){	x=(x<<3)+(x<<1)+a-'0'; a=getchar();}return x*y;
}
#define N 200
int dis[N],tot,ans; 
int fa[N];
bool vis[N];
int n;  
int findfa(int x){
	int p = x,temp; 
	while ( p != fa[p]){
		p = fa[p];
	}
	while ( x != p ){
		temp = fa[x];
		fa[ x ] = p ; 
		x = temp ; 	
	} 
	return fa[x];
}
struct Edge{
	int u,v,w; 
}e[N*N];
bool cmp(Edge a,Edge b){
	return a.w < b.w; 
}
void kruskal(){
	sort(e+1,e+tot+1,cmp);
	rep(aai,1,tot){
		int ufa = findfa(e[aai].u);
		int vfa = findfa(e[aai].v);
		if ( ufa != vfa ){
			fa[ufa] = vfa; 
			ans += e[aai].w; 
		}
	}
}
int main()
{
//	freopen("1.txt","r",stdin);
	srand((int)time(0));
//	std::ios::sync_with_stdio(false);
	while ( scanf("%d",&n) && n ){
		mset(e,0x3f); 
		rep(i,0,N-1) fa[i] = i; 
		tot = 0; ans = 0; 
		char s[ 5 ],en[5];int w,m; 
		rep(i,1,n-1){
			scanf("%s%d",s,&m);
			rep(j,1,m){
				scanf("%s%d", en, &w);
                e[++tot].u = s[0]-'A';
                e[tot].v = en[0]-'A';
                e[tot].w = w; 
			}
		}
		kruskal();
		cout<<ans<<endl; 
	}
	return 0;
}