toj 最小生成树集萃
1924 jungle road
#include
<
iostream
>
#include
<
cstring
>
using
namespace
std;
int
path[
30
][
30
];
int
cost[
30
];
int
flag[
30
];
int
prim(
int
n)
{
int sum=0; int i,j,min,v; v=0; flag[v]=1; for(i=0;i<n-1;i++)
{ for(j=0;j<n;j++) if(!flag[j]&&path[v][j]<cost[j]) cost[j]=path[v][j]; min=1<<30; for(j=0;j<n;j++) if(!flag[j]&&cost[j]<min) { min=cost[j]; v=j;
} flag[v]=1; sum+=min; } return sum ;
}
int
main()
{ int n,i,j,v,min,m,c; char ch; while(scanf("%d",&n)!=EOF&&n) { memset(path,0x1f,sizeof(path)); memset(cost,0x1f,sizeof(cost)); memset(flag,0,sizeof(flag)); for(i=0;i<n;i++) path[i][i]=0; for(i=0;i<n-1;i++) { getchar(); scanf("%c",&ch); scanf("%d",&m); for(j=0;j<m;j++) { getchar(); scanf("%c",&ch); scanf("%d",&c); path[i][ch-'A']=path[ch-'A'][i]=c; } } printf("%d\n",prim(n)); } return 0;}
#include
<
iostream
>
#include
<
iomanip
>
#include
<
cmath
>
using
namespace
std;
int
x[
501
];
int
y[
501
];
struct
node
{ int s,e; int d; bool operator<(const node& a)const { return d<a.d; }}
edges[
130000
];
int
father[
505
];
int
n,m;
int
find(
int
i)
{ if(father[i]==i) return i; else return father[i]=find(father[i]);}
void
unin(
int
i,
int
j)
{ int a=find(i); int b=find(j); father[a]=b;}
int
f(
int
k)
{ int i,j; j=0; for(i=0;i<k&&j<m-n;i++) if(find(father[edges[i].s])!=find(father[edges[i].e])) { unin(edges[i].s,edges[i].e); j++; if(j==m-n) return edges[i].d; }}
int
main()
{ int i,j,k,cas_num; scanf("%d",&cas_num); while(cas_num--) { scanf("%d%d",&n,&m); for(i=0;i<m;i++) father[i]=i; k=0; for(i=0;i<m;i++) { cin>>x[i]>>y[i]; for(j=0;j<i;j++) { edges[k].s=j; edges[k].e=i; edges[k].d=(x[j]-x[i])*(x[j]-x[i])+(y[j]-y[i])*(y[j]-y[i]); k++; } } sort(edges,edges+k); cout<<fixed<<setprecision(2)<<sqrt(f(k)*1.0)<<endl; } return 0;}
1830. Tangled in Cables
#include
<
iostream
>
#include
<
map
>
#include
<
algorithm
>
#include
<
string
>
using
namespace
std;
struct
node
{ int s,e; double d; bool operator<(const node& a)const { return d<a.d; }}
edges[
60000
];
int
father[
505
];
int
find(
int
i)
{ if(father[i]==i) return i; else return father[i]=find(father[i]);}
void
unin(
int
i,
int
j)
{ int a=find(i); int b=find(j); father[a]=b;}
void
f(
double
total,
int
n,
int
m)
{ int i,j; double sum=0; j=0; for(i=0;i<m&&j<n-1&&sum<total;i++) if(find(father[edges[i].s])!=find(father[edges[i].e])) { unin(edges[i].s,edges[i].e); sum+=edges[i].d; j++; } if(j==n-1) printf("Need %.1lf miles of cable\n",sum); else printf("Not enough cable\n");}
int
main()
{ map<string,int>mm; int i,n,m; double cost,total; double ans; string s1,s2; char ch1[21],ch2[21]; while(cin>>total) { scanf("%d",&n); for(i=0;i<n;i++) father[i]=i; for(i=0;i<n;i++) { scanf("%s",ch1); s1=ch1; mm[s1]=i; } scanf("%d",&m); for(i=0;i<m;i++) { scanf("%s %s",ch1,ch2); scanf("%lf",&cost); s1=ch1; s2=ch2; edges[i].s=mm[s1]; edges[i].e=mm[s2]; edges[i].d=cost; } sort(edges,edges+m); f(total,n,m); } return 0;}
2288. Highways
#include
<
iostream
>
#include
<
algorithm
>
using
namespace
std;
int
x[
760
],y[
760
];
int
father[
760
];
int
find(
int
i)
{ if(father[i]==i) return i; else return father[i]=find(father[i]);}
void
unin(
int
i,
int
j)
{ int a=find(i); int b=find(j); father[a]=b;}
struct
node
{ int s,e; int d; bool operator <(const node& a)const { if(d!=a.d) return d<a.d; else return s<a.s; }}
edges[
300000
];
void
kruscal(
int
n,
int
k)
{ int j=0; for(int i=0;i<k&&j<n-1;i++) if(find(edges[i].s)!=find(edges[i].e)) { unin(edges[i].s,edges[i].e); printf("%d %d\n",edges[i].s,edges[i].e); j++; }}
int
main()
{ int n,m,i,j,k,a,b; while(scanf("%d",&n)!=EOF) { for(i=0;i<=n;i++) father[i]=i; k=0; for(i=1;i<=n;i++) { scanf("%d%d",&x[i],&y[i]); for(j=1;j<i;j++) { edges[k].s=j; edges[k].e=i; edges[k].d=(x[j]-x[i])*(x[j]-x[i])+(y[j]-y[i])*(y[j]-y[i]); k++; } } sort(edges,edges+k); scanf("%d",&m); for(i=0;i<m;i++) { scanf("%d%d",&a,&b); unin(a,b); } kruscal(n,k); } return 0;}
TOJ 2172
#include
<
iostream
>
#include
<
map
>
#include
<
algorithm
>
#include
<
string
>
using
namespace
std;
struct
node
{ int s,e; int d; bool operator<(const node& a)const { return d<a.d; }}
edges[
60000
];
int
father[
5005
];
int
n,t;
int
find(
int
i)
{ if(father[i]==i) return i; else return father[i]=find(father[i]);}
void
unin(
int
i,
int
j)
{ int a=find(i); int b=find(j); father[a]=b;}
int
f(
int
k,
int
n)
{ int i,j,sum; j=sum=0; for(i=0;i<k&&j<n-1;i++) if(find(father[edges[i].s])!=find(father[edges[i].e])) { unin(edges[i].s,edges[i].e); sum+=edges[i].d; j++; } return sum;}
int
main()
{ map<string,int>m; int i,j,cost,k; int ans; string s1,s2; char ch1[11],ch2[11]; while(scanf("%d%d",&n,&t)!=EOF) { j=0; k=t; for(i=0;i<=n;i++) father[i]=i; for(i=0;i<t;i++) { getchar(); scanf("%s %s",&ch1,&ch2); scanf("%d",&cost); s1=ch1; s2=ch2; map<string,int>::iterator it; it=m.find(s1); if(it==m.end()) { m[s1]=j; edges[k].s=0; edges[k].e=j++; edges[k].d=10; k++; } it=m.find(s2); if(it==m.end()) { m[s2]=j; edges[k].s=0; edges[k].e=j++; edges[k].d=10; k++; } edges[i].s=m[s1]; edges[i].e=m[s2]; edges[i].d=cost; } ans=(n-j+1)*10; sort(edges,edges+k); ans+=f(k,j); printf("The total cost is %d Yuan %d Jiao.\n",ans/10,ans%10); } return 0;}