/*
* 2026년도 한국정보올림피아드 2차 대회
*
* 게임 (game)
* 초등부 4번 / 중등부 3번
* Main Correct Solution (C++)
*/

#include <iostream>
#include <vector>
#include <queue>
using namespace std;

long long maxk[200'010];
long long sum[200'010];
int vis[200'010];
int A[200'010];
vector<pair<int, int>> adj[200'010];

signed main() {
	ios::sync_with_stdio(false), cin.tie(nullptr);
	int N, M, Q;
	cin >> N >> M >> Q;
	for (int i = 1; i <= N; i++) cin >> A[i];
	for (int i = 1; i <= M; i++) {
		int a, b, c;
		cin >> a >> b >> c;
		adj[a].emplace_back(b, c);
		adj[b].emplace_back(a, c);
	}

	long long cur = 1e18;

	priority_queue<pair<long long, int>> pq;
	queue<int> q;

	auto add = [&](int x) {
		for (auto& [v, c] : adj[x]) {
			if (vis[v]) continue;
			sum[v] += c;
			if (sum[v] >= cur) {
				maxk[v] = cur;
				vis[v] = 1;
				q.push(v);
			}
			else pq.emplace(sum[v], v);
		}
		};

	for (int i = 1; i <= N; i++) {
		if (A[i] == 1) {
			maxk[i] = 1e18;
			vis[i] = 1;
			q.push(i);
		}
	}
	while (1) {
		while (q.size()) {
			int t = q.front();
			q.pop();
			add(t);
		}
		if (pq.empty()) break;
		int t = pq.top().second;
		pq.pop();
		if (vis[t]) continue;
		maxk[t] = cur = sum[t];
		vis[t] = 1;
		q.push(t);
	}
	for (int i = 1; i <= Q; i++) {
		int s;
		long long k;
		cin >> s >> k;
		if (maxk[s] >= k) cout << "YES\n";
		else cout << "NO\n";
	}
	return 0;
}