[2016-04-13] [HDU] [1233] [or Smooth works]

• Time: 2016-04-13-23:56:49
• Title Number: [2016-04-13][hdu][1233][or smooth works]
• The main idea: to find the minimum spanning tree
• Analysis: Direct Kruskal

  
 

   
  

  
#include<cstdio>
   
  

  
#include<algorithm>
   
  

  
using namespace std;
   
  

  
const int maxn = 100 + 10;
   
  

  
int fa[maxn];
   
  

  
struct Edge{
   
  

  
  int    v   c  ;   
   
  

  
  edge   ( int   _u  =    0   int   _v  =  0   int   _c  =  0  ):  u   _u   v   _v   c   _c  
   
  

  
 bool operator < (const Edge & a)const{
   
  

  
 return c < a.c;
   
  

  
 }
   
  

  
}e[maxn*maxn];
   
  

  
int fnd(int x){
   
  

  
 return x == fa[x] ? x: (fa[x] = fnd(fa[x]));
   
  

  
}
   
  

  
void ini(int n){
   
  

  
 for(int i = 0 ; i <= n ; ++i){
   
  

  
 fa[i] = i;
   
  

  
 } 
   
  

  
}
   
  

  
int main(){
   
  

  
 int n;
   
  

  
 //freopen("in.txt","r",stdin);
   
  

  
 while(~scanf("%d",&n) && n){
   
  

  
 int a,b,c;
   
  

  
 ini(n);
   
  

  
 for(int i = 0 ; i < n * (n-1)/2;++i){
   
  

  
 scanf("%d%d%d",&a,&b,&c);
   
  

  
 e[i] = Edge(a,b,c); 
   
  

  
 }
   
  

  
 sort(e,e+n*(n-1)/2);
   
  

  
 int cnt = 0,ans = 0;
   
  

  
  for   ( int   i  =    0    ;   I  <   n  * ( n  -   1  )/   2  ;++  i    
   
  

  
 int f1 = fnd(e[i].u);
   
  

  
 int f2 = fnd(e[i].v);
   
  

  
 if(f1 != f2){
   
  

  
 fa[f1] = fa[f2];
   
  

  
 ans += e[i].c;
   
  

  
 ++cnt;
   
  

  
 }
   
  

  
 if(cnt == n - 1) break; 
   
  

  
 }
   
  

  
 printf("%d\n",ans);
   
  

  
 }
   
  

  
 return 0;
   
  

  
}
  
 

From for notes (Wiz)

[2016-04-13] [HDU] [1233] [or Smooth works]