hdu3938 Portal 离线+并查集

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

int m, n, q;
const int maxn = 50005;
int fa[maxn];
int Rank[maxn];

void init(){
    for (int i = 1; i <= n; i++){
        Rank[i] = 1;
        fa[i] = i;
    }
}

struct  node
{
    int u;    //路的前端
    int v;    //路的后端
    int l;    //成本
}edge[maxn];

struct Q
{
    int l, id, ans;
}que[maxn];

bool cmp(node a, node b){
    return a.l < b.l;
}

bool cmp1(Q a, Q b){
    return a.l < b.l;    //从小到大排序
}

bool cmp2(Q a, Q b){
    return a.id < b.id;
}

int find(int x){
    if (x == fa[x])
        return x;
    return fa[x] = find(fa[x]);
}

int Set_Union(int x, int y){
    int fx = find(x);
    int fy = find(y);
    if (fx == fy)
        return 0;
    fa[fy] = fx;
    int t = Rank[fx];
    Rank[fx] = Rank[fx] + Rank[fy];
    return t*Rank[fy];
}

int main(){
    while (~scanf("%d%d%d", & n, &m, &q)){
        init();
        que[0].ans = 0;
        for (int i = 1; i <= m; i++){
            scanf("%d%d%d", &edge[i].v, &edge[i].u, &edge[i].l);
        }
        for (int i = 1; i <= q; i++){
            scanf("%d", &que[i].l);
            que[i].id = i;
            que[i].ans = 0;
        }
        sort(edge + 1,edge + 1 + m, cmp);
        sort(que + 1, que + 1 + q, cmp1);
        int cur = 1;
        for (int i = 1; i <= q; i++){
            que[i].ans = que[i - 1].ans;
            while (edge[cur].l <= que[i].l&&cur <= m){
                que[i].ans += Set_Union(edge[cur].u, edge[cur].v);
                cur++;
            }
        }
        sort(que + 1, que + 1 + q, cmp2);
        for (int i = 1; i <= q; i++){
            printf("%d\n", que[i].ans);
        }

    }
    //system("pause");
    return 0;
}