hdu 1233はやはり融通工事（最小生成樹、prm、優先列、kruskyalそして検索集）

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;
int N;
int vis[110];
int map[110][110];
struct node {
    int x, y, dis;
    friend bool operator < (node a, node b) {
        return a.dis > b.dis;
    }
};
int cnt = 0, ans = 0;
int main() {
	//freopen("input.txt", "r", stdin);
    while(~scanf("%d", &N) && N) {
    	if(N == 1) {
			printf("0
");
			continue;
		}
        cnt = N;
        ans = 0;
        int i;
        int x, y, z;
        memset(map, 0, sizeof(map));
        for(i = 0; i < N * (N - 1) / 2; i++) {
            scanf("%d %d %d", &x, &y, &z);
            map[x][y] = z;
            map[y][x] = z;
        }
        memset(vis, 0, sizeof(vis));
        priority_queue <node> q;
        node now, next;
        for(i = 1; i <= N; i++) {
            if(map[1][i]) {
                now.x = 1, now.y = i, now.dis = map[1][i];
                q.push(now);
            }
        }
        vis[1] = 1;
        cnt--;
        while(!q.empty()) {
            now = q.top();
            q.pop();
            if(vis[now.y] == 1) continue;
            vis[now.y] = 1;
            ans += now.dis;
            cnt--;
            if(cnt == 0) {
                printf("%d
", ans);
                break;
            }
            int i;
            for(i = 1; i <= N; i++) {
                if(map[now.y][i] && vis[i] == 0) {
                    next.x = now.y, next.y = i, next.dis = map[next.x][next.y];
                    q.push(next);
                }
            }
        }
    }
    return 0;
}

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int n, m;
struct node {
	int s, e, w;
}edge[5050];
int f[5050];
int cmp(node a, node b) {
	return a.w < b.w;
}
int find(int x) {
	if(f[x] == -1) return x;
	return f[x] = find(f[x]);
}
int main() {
	while(~scanf("%d", &n) , n) {
		m = n * (n - 1) / 2;
		int i;
		int s, e, w;
		for(i = 1; i <= m; i++) {
			scanf("%d %d %d", &s, &e, &w);
			edge[i].s = s, edge[i].e = e, edge[i].w = w;
		}
		memset(f, -1, sizeof(f));
		sort(edge + 1, edge + m + 1, cmp);
		int sum = 0;
		for(i = 1; i <= m; i++) {
			int t1 = find(edge[i].s);
			int t2 = find(edge[i].e);
			if(t1 != t2) {
				f[t1] = t2;
				sum += edge[i].w;
			}
		}
		printf("%d
", sum);
	}
	return 0;
}