最小生成树 之 CODE[VS] 1078 最小生成树

/*
  最小生成树
  Prim算法(邻接矩阵)
*/
 1 #include <iostream>
 2 #include <cstdlib>
 3 #include <cstdio>
 4 #include <cstddef>
 5 #include <iterator>
 6 #include <algorithm>
 7 #include <string>
 8 #include <locale>
 9 #include <cmath>
10 #include <vector>
11 #include <cstring>
12 #include <map>
13 #include <utility>
14 #include <queue>
15 #include <stack>
16 #include <set>
17 #include <functional>
18 using namespace std;
19 typedef pair<int, int> PII; 
20 const int INF = 0x3f3f3f3f;
21 const int modPrime = 3046721;
22 const double eps = 1e-9;
23 const int MaxN = 110;
24 const int MaxM = 110;
25 
26 int N;
27 int cost[MaxN][MaxN];
28 int minCost[MaxN];
29 bool used[MaxN];
30 
31 
32 void Solve()
33 {
34     fill(minCost, minCost + N, INF);
35     fill(used, used + N, false);
36     minCost[0] = 0;
37     int ans = 0;
38 
39     while (true)
40     {
41         int v = -1;
42         for (int i = 0; i < N; ++i)
43         {
44             if (!used[i] && (-1 == v || minCost[i] < minCost[v]))
45             {
46                 v = i;
47             }
48         }
49         if (v == -1)
50         {
51             break;
52         }
53         used[v] = true;
54         ans += minCost[v];
55         for (int i = 0; i < N; ++i)
56         {
57             minCost[i] = min(minCost[i], cost[v][i]);
58         }
59     }
60 
61     printf("%d\n", ans);
62 }
63 
64 int main()
65 {
66 #ifdef HOME
67     freopen("in", "r", stdin);
68     //freopen("out", "w", stdout);
69 #endif
70 
71     scanf("%d", &N);
72     for (int i = 0; i < N; ++i)
73     {
74         for (int j = 0; j < N; ++j)
75         {
76             scanf("%d", &cost[i][j]);
77         }
78     }
79     Solve();
80 
81 #ifdef HOME
82     cerr << "Time elapsed: " << clock() / CLOCKS_PER_SEC << " ms" << endl;
83     _CrtDumpMemoryLeaks();
84 #endif
85     return 0;
86 }

 

 
posted @ 2015-12-16 21:04  JmingS  阅读(308)  评论(0编辑  收藏  举报