#include <iostream>
#include <cstring>
using namespace std;
const int N = 2e5 + 5, M = 4e5 + 5;
int n, m, a, b, h[N], e[M], ne[M], idx, root = 1, dep[N], fa[N][19], die;
double d[N], dist[N], w[M], c, ans;
bool st[N];
void add(int a, int b, double c)
{
    e[idx] = b, ne[idx] = h[a], w[idx] = c, h[a] = idx++;
}
void dfs(int u, double val)
{
    dist[u] = val, st[u] = true;
    for (int i = h[u]; ~i; i = ne[i])
        if (!st[e[i]])
            dfs(e[i], val * w[i]);
}
void dfs_lca(int u, int father)
{
    dep[u] = dep[father] + 1, fa[u][0] = father;
    for (int i = 1; i <= 18; i++)
        fa[u][i] = fa[fa[u][i - 1]][i - 1];
    for (int i = h[u]; ~i; i = ne[i])
        if (e[i] != father)
            dfs_lca(e[i], u);
}
int lca(int u, int v)
{
    if (dep[u] < dep[v])
        swap(u, v);
    for (int i = 18; i >= 0; i--)
        if (dep[fa[u][i]] >= dep[v])
            u = fa[u][i];
    if (u == v)
        return v;
    for (int i = 18; i >= 0; i--)
        if (fa[u][i] != fa[v][i])
            u = fa[u][i], v = fa[v][i];
    return fa[u][0];
}
int main()
{
    ios::sync_with_stdio(false), cin.tie(0);
    cin >> n >> m, memset(h, -1, sizeof(h));
    for (int i = 1; i <= n; i++)
        cin >> d[i];
    for (int i = 1; i < n; i++)
        cin >> a >> b >> c, add(a, b, c), add(b, a, c), st[b] = true;
    while (st[root])
        root++;
    memset(st, false, sizeof(st)), dfs(root, 1), dfs_lca(root, 0);
    while (m--)
    {
        cin >> a >> b, die = lca(a, b);
        ans = dist[a] * dist[b] * d[a] / dist[die] / dist[die];
        if (ans - (int)ans < 1e-8)
            cout << "Yes\n";
        else
            cout << "No\n";
    }
}

输出了一些信息，看上去样例是没问题的...