最小生成树几道模版题（hdu1301 hdu1879)

http://acm.hdu.edu.cn/showproblem.php?pid=1879

prime算法

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 1 #include <iostream>

 2 #include<cstdio>

 3 #include<string.h>

 4 #define INF 0x3f3f3f3f

 5 using namespace std;

 6 int w[101][101],visit[101],low[101],sum = 0;

 7 void prime(int n)

 8 {

 9     int i,j,k,m;

10     memset(visit,0,sizeof(visit));

11     visit[1] = 1;

12     for(i = 2 ;i <= n ; i++)

13     low[i] = w[1][i];

14     for(i = 1 ; i <= n ;i++)

15     {

16         m = INF;

17         for(j = 1; j <= n ; j++)

18         if(!visit[j]&&m>low[j])

19         m = low[k=j];

20         if(m == INF)

21         break;

22         sum+=m;

23         visit[k] = 1;

24         for(j = 1; j <= n ; j++)

25         if(!visit[j]&&low[j]>w[k][j])

26         low[j] = w[k][j];

27     }

28 }

29 int main()

30 {

31     int i,j,k,n,m,a,b,c,d;

32     while(scanf("%d",&n)&&n)

33     {

34         k = n*(n-1)/2;

35         memset(w,INF,sizeof(w));

36         sum = 0;

37         while(k--)

38         {

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

40             if(d==1)

41             {

42                 w[a][b] = 0;

43                 w[b][a] = 0;

44             }

45             else

46             {

47                 if(w[a][b]>c)

48                 {

49                     w[a][b] = c;

50                     w[b][a] = c;

51                 }

52             }

53         }

54         prime(n);

55         printf("%d\n",sum);

56     }

57     return 0;

58 }

Kruskal

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 1 #include <iostream>

 2 #include<cstdio>

 3 #include<string.h>

 4 #include<algorithm>

 5 struct node

 6 {

 7     int u,v,w;

 8 }q[5001];

 9 int father[101];

10 using namespace std;

11 bool cmpp(struct node a,struct node b)

12 {

13     return a.w<b.w;

14 }

15 int find(int x)

16 {

17     if(x!=father[x])

18     father[x] = find(father[x]);

19     return father[x];

20 }

21 int main()

22 {

23     int i,j,k,f,n,m,o;

24     while(scanf("%d", &n)&&n)

25     {

26         for(i = 1; i <= n ; i++)

27         father[i] = i;

28         int num = 0;

29         int sum = 0;

30        for(i = 1; i <= n*(n-1)/2 ; i++)

31        {

32            scanf("%d%d%d%d",&q[i].u,&q[i].v,&q[i].w,&o);

33            if(o==1)

34            {

35                if(find(q[i].u)!=find(q[i].v))

36                {

37                    father[find(q[i].u)] = find(q[i].v);

38                    num++;

39                }

40            }

41        }

42        sort(q+1,q+n*(n-1)/2,cmpp);

43        for(i = 1; i <= n*(n-1)/2&&num<n ; i++)

44        if(find(q[i].u)!=find(q[i].v))

45        {

46            father[find(q[i].u)] = find(q[i].v);

47            sum+=q[i].w;

48            num++;

49        }

50        printf("%d\n",sum);

51     }

52     return 0;

53 }

http://acm.hdu.edu.cn/showproblem.php?pid=1301

Kruskal

View Code

 1 #include <iostream>

 2 #include<cstdio>

 3 #include<algorithm>

 4 #include<string.h>

 5 using namespace std;

 6 struct node

 7 {

 8     int x,y,w;

 9 }y[100];

10 int father[100],num,sum;

11 bool cmpp(struct node a,struct node b)

12 {

13     return a.w<b.w;

14 }

15 int find(int x)

16 {

17     if(x!=father[x])

18     father[x] = find(father[x]);

19     return father[x];

20 }

21 void union1(int x,int y,int z)

22 {

23     father[x] = y;

24     sum+=z;

25     num++;

26 }

27 int main()

28 {

29     int n,m,i,j,k,g,co[30];

30     char c1,c2;

31     while(scanf("%d",&n)&&n)

32     {

33         g = 0;

34         num = 0;

35         sum = 0;

36         int x = 0;

37         memset(co,0,sizeof(co));

38         x = n;

39         n--;

40         while(n--)

41         {

42             scanf("%*c%c %d",&c1,&m);

43             co[c1-'A']++;

44             while(m--)

45             {

46                 g++;

47                 scanf("%*c%c %d",&c2,&k);

48                 co[c2-'A']++;

49                 y[g].x = c1-'A';

50                 y[g].y = c2-'A';

51                 y[g].w = k;

52             }

53         }

54         sort(y+1,y+g+1,cmpp);

55         for(i = 0 ; i < x ; i++)

56         father[i] = i;

57         for(i = 1; i <= g&&num<x ; i++)

58         {

59             if(find(y[i].x)!=find(y[i].y))

60             {

61                 union1(find(y[i].x),find(y[i].y),y[i].w);

62             }

63         }

64         printf("%d\n",sum);

65     }

66     return 0;

67 }