打了一个最大生成树+dfs，60分成功tle

#include <bits/stdc++.h>

using namespace std;

const int maxn = 10005;

const int maxm = 50005;

int n, m, cnt = 0;

struct edge

{

	int from, to, value;

	bool operator < (const edge b) const {

		return this->value > b.value;

	}

}es[maxm];

vector<edge> G[maxn];

struct car

{

	int from, to;

}cs[30001];

int q;

void read() {

	cin >> n >> m;

	for(int i = 1; i <= m; i++) {

		int x, y, z;

		cin >> x >> y >> z;

		es[cnt].from = x;

		es[cnt].to = y;

		es[cnt].value = z;

		cnt++;

	}

	cin >> q;

	for(int i = 1; i <= q; i++) cin >> cs[i].from >> cs[i].to;

}

int fa[maxn];

int find(int x) {

	return x == fa[x] ? x : fa[x] = find(fa[x]);

}

void kruskal() {

	sort(es, es+cnt);

	for(int i = 1; i <= n; i++) fa[i] = i;

	for(int i = 0; i < cnt; i++) {

		int x = es[i].from; int y = es[i].to;

		int fx = find(x); int fy = find(y);

		if(fx == fy) {

			es[i].value = -1;

			continue;

		}

		else fa[fx] = fy;

	}

}

void build_tree() {

	sort(es, es+cnt);

	for(int i = 0; i < cnt; i++) {

		if(es[i].value != -1) {

			int x = es[i].from;

			int y = es[i].to;

			G[x].push_back({x, y, es[i].value});

			G[y].push_back({y, x, es[i].value});

		}

		else break;

	}

}

int mini = 0x3f3f3f;

int vis[maxn];

void dfs(int from, int to, int m) {

	vis[from] = 1;

	if(from == to) {mini = m; return;}

	vector<edge>::iterator it;

	for(it = G[from].begin(); it != G[from].end(); it++) {

		edge &e = *it;

		if(!vis[e.to]) {

			dfs(e.to, to, min(m, e.value));

		}

	}

}

void solve() {

	for(int i = 1; i <= q; i++) {

		int x = cs[i].from;

		int y = cs[i].to;

		mini = 0x3f3f3f;

		memset(vis, 0, sizeof(vis));

		dfs(x, y, 0x3f3f3f);

		if(mini == 0x3f3f3f) cout << -1;

		else cout << mini;

		cout << endl;

	}

}

int main() {

//	freopen("input.in", "r", stdin);

	read();

	kruskal();

	build_tree();

	solve();

	return 0;

}