POJ 1251 Jungle Roads minimal spanning tree

POJ 1251 Jungle Roads minimal spanning tree

The question is to give your graph and then find the value of the minimum spanning tree. Note the input.

Idea: kruskal water stops using the bare minimum spanning tree. I did not write the minimum spanning tree for a long time. I thought about it carefully and wrote it out.

Code:

 

1. # Include
2. # Include
3. # Include
4. # Include
5. # Include
6. Using namespace std;
7.  
8. # Define CLR (arr, val) memset (arr, val, sizeof (arr ))
9. Const int N = 32;
10. Vector Vv [N];
11. Int numedge, father [N];
12. Struct edge {
13. Int leftp, rightp, value;
14. } Ee [1, 1000];
15. Bool cmp (edge a, edge B ){
16. Return a. value <B. value;
17. }
18. Int find (int x ){
19. If (x = father [x])
20. Return father [x];
21. Return find (father [x]);
22. }
23. Bool union_set (int lp, int rp ){
24. Int sequence = find (lp );
25. Int frp = find (rp );
26. If (records = frp ){
27. Return false;
28. }
29. Else {
30. Father [frp] = frp;
31. Return true;
32. }
33. }
34. Int kruskal (){
35. Int sum = 0;
36. For (int I = 0; I <numedge; ++ I ){
37. Int lp = ee [I]. leftp;
38. Int rp = ee [I]. rightp;
39. If (union_set (lp, rp ))
40. Sum + = ee [I]. value;
41. }
42. Return sum;
43. }
44. Int main (){
45. // Freopen(1.txt, r, stdin );
46. Int n;
47. While (scanf (% d, & n ){
48. Char ch;
49. Int num, x;
50. Numedge = 0;
51. For (int I = 1; I <n; ++ I ){
52. Cin> ch;
53. Scanf (% d, & num );
54. While (num --){
55. Cin> ch;
56. Scanf (% d, & x );
57. Int y = (int) (ch-'A' + 1 );
58. Ee [numedge]. leftp = I;
59. Ee [numedge]. rightp = y;
60. Ee [numedge]. value = x;
61. Numedge ++;
62. }
63. }
64. Sort (ee, ee + numedge, cmp );
65. For (int I = 1; I <N; ++ I)
66. Father [I] = I;
67. Int ans = kruskal ();
68. Printf (% d, ans );
69. }
70. Return 0;
71. }