ZOJ 1203 Swordfish MST

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http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=1203

大意：

给出一些点，求MST

把这几天的MST一口气发上来。

kruskal

#include<cstdio>#include<cmath>#include<algorithm>using namespace std;const int MAXN=101;const int INF=9999999;int fa[MAXN];struct point{double x,y;}ship[MAXN];struct dot{int x,y;double dis;}dis[MAXN*MAXN];int find(int cur){return fa[cur]==cur?cur:fa[cur]=find(fa[cur]);}bool operator < (const dot &a,const dot& b){return a.dis<b.dis;}int main(){int n,kase=1;while(~scanf("%d",&n),n){if(kase!=1)printf("\n");int i,j;for(i=1;i<=n;i++)scanf("%lf%lf",&ship[i].x,&ship[i].y);int len=0;for(i=1;i<=n;i++){for(j=i+1;j<=n;j++){dis[len].x=i;dis[len].y=j;dis[len].dis=sqrt((ship[j].y -ship[i].y) *(ship[j].y -ship[i].y) + (ship[j].x -ship[i].x)*(ship[j].x -ship[i].x));len++;}}for(i=1;i<=n;i++)fa[i]=i;sort(dis,dis+len);double ans=0;for(i=0;i<len;i++)   {int rootx=find(dis[i].x);int rooty=find(dis[i].y);if(rootx!=rooty){ans+=dis[i].dis;fa[rootx]=rooty;}}printf("Case #%d:\n",kase++);printf("The minimal distance is: %.2lf\n",ans);}return 0;}

prim

#include<cstdio>#include<cmath>const int MAXN=101;const int INF=9999999;double map[MAXN][MAXN];double dis[MAXN];struct point{double x,y;}ship[MAXN];void prim(int n){for(int i=1;i<=n;i++)dis[i]=INF;bool vis[MAXN]={0};int cur=1;            vis[cur]=1;dis[cur]=0;int i,j;for(i=1;i<=n;i++){double mini=INF;for(j=1;j<=n;j++)if(!vis[j] && dis[j] > map[cur][j])dis[j]=map[cur][j];for(j=1;j<=n;j++)if(!vis[j] && mini > dis[j])mini=dis[cur=j];vis[cur]=true;}}int main(){int n,kase=1;while(~scanf("%d",&n),n){if(kase!=1)printf("\n");int i,j;for(i=1;i<=n;i++)scanf("%lf%lf",&ship[i].x,&ship[i].y);for(i=1;i<=n;i++){for(j=1;j<=n;j++){map[i][j]=map[j][i] = sqrt((ship[j].y -ship[i].y) *(ship[j].y -ship[i].y) + (ship[j].x -ship[i].x)*(ship[j].x -ship[i].x));}}prim(n);double ans=0,ans2=0;//=map[a][b];for(i=1;i<=n;i++)ans+=dis[i];printf("Case #%d:\n",kase++);printf("The minimal distance is: %.2lf\n",ans);}}

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