HDU5877 线段树

//看看会不会爆int!数组会不会少了一维！
//取物问题一定要小心先手胜利的条件
#include <bits/stdc++.h>
using namespace std;
#define LL long long
#define ALL(a) a.begin(), a.end()
#define pb push_back
#define mk make_pair
#define fi first
#define se second
const int maxn = 4e5 + 5;
LL a[maxn], b[maxn], d[maxn], tree[maxn * 4];
LL n, m, k, lenb, ans;
vector<int> E[maxn];

int query(int o, int l, int r, int ql, int qr){
    if (l >= ql && r <= qr){
        return tree[o];
    }
    int cnt = 0;
    int mid = (l + r) / 2;
    if (ql <= mid) cnt += query(o << 1, l, mid, ql, qr);
    if (qr > mid) cnt += query(o << 1 | 1, mid + 1, r, ql, qr);
    return cnt;
}

inline void push_up(int o){
    int lb = o << 1, rb = o << 1 | 1;
    tree[o] = tree[lb] + tree[rb];
}

void update (int o, int l, int r, int pos, int val){
    if (l == r && l == pos) {
        tree[o] += val;
        return ;
    }
    int mid = (l + r) / 2;
    if (pos <= mid) update(o << 1, l, mid, pos, val);
    if (pos > mid) update(o << 1 | 1, mid + 1, r, pos, val);
    push_up(o);
}

void dfs(int u){
    int pos = lower_bound(b + 1, b + 1 + m, a[u]) - b;
    int posk = lower_bound(b + 1, b + 1 + m, k / a[u]) - b;
    ans += query(1, 1, lenb, 1, posk);
    int len = E[u].size();
    update(1, 1, lenb, pos, 1);
    for (int i = 0; i < len; i++){
        int v = E[u][i];
        dfs(v);
    }
    update(1, 1, lenb, pos, -1);
}

int main(){
    int t; cin >> t;
    while (t--){
        memset(d, 0, sizeof(d));
        memset(tree, 0, sizeof(tree));
        scanf("%I64d%I64d", &n, &k);
        for (int i = 1; i <= n; i++){
            scanf("%I64d", a + i);
            b[i] = a[i];
            E[i].clear();
        }
        m = n;
        for (int i = 1; i <= n; i++) b[++m] = k / a[i];
        
        sort(b + 1, b + 1 + m);
        lenb = unique(b + 1, b + 1 + m) - b - 1;///序列长度1~n
        ///printf("lenb = %d\n", lenb);
        for (int i = 1; i <= n - 1; i++){
            int u, v; scanf("%d%d", &u, &v);
            E[u].pb(v);
            d[v]++;
        }
        ans = 0;
        for (int i = 1; i <= n; i++){
            if (d[i] == 0){
                dfs(i);
                break;
            }
        }
        printf("%I64d\n", ans);
    }
    return 0;
}