输入：顶点个数n和边数m，然后输入m行，每行输入格式：u v w 分别表示两个顶点和这个边的权值，顶点序号从1开始
输出：一次选择的各条边和最终的最小生成树的权值
1 #include <cstdio> 2 #include <cstdlib> 3 #include <algorithm> 4 using namespace std; 5 #define MAXN 1000 6 #define MAXM 1000 7 int parent[MAXN], n, m; 8 typedef struct Edge { 9 int u, v, w; 10 bool operator < (const Edge &other) const { 11 return w < other.w; 12 } 13 }Edge; 14 Edge edge[MAXM]; 15 void init() { 16 for (int i = 1; i <= n; ++i) parent[i] = -1; 17 } 18 int Find(int x) { 19 int s = x, tmp; 20 while (parent[s] >= 0) s = parent[s]; 21 while (s != x) { 22 tmp = parent[x]; parent[x] = s; x = tmp; 23 } 24 return s; 25 } 26 void Union(int a, int b) { 27 int x = Find(a), y = Find(b), tmp = parent[x] + parent[y]; 28 if (parent[x] < parent[y]) { 29 parent[y] = x; parent[x] = tmp; 30 } else { 31 parent[x] = y; parent[y] = tmp; 32 } 33 } 34 void kruscal() { 35 int cnt = 0, sum = 0, i, u, v, w; 36 for (i = 0; i < m; ++i) { 37 u = edge[i].u; v = edge[i].v; w = edge[i].w; 38 if (Find(u) != Find(v)) { 39 cnt++; sum += w; printf("%d %d %d\n", u, v, w); Union(u, v); 40 } 41 if (cnt == n - 1) break; 42 } 43 printf("%d\n", sum); 44 } 45 int main(void) { 46 freopen("kruscal.in", "r", stdin); 47 while (~scanf("%d%d", &n, &m)) { 48 int i, u, v, w; 49 for (i = 0; i < m; ++i) { 50 scanf("%d%d%d", &u, &v, &w); edge[i].u = u; edge[i].v = v; edge[i].w = w; 51 } 52 init(); sort(edge, edge+m); kruscal(); 53 } 54 55 return 0; 56 }
呵呵
