蒟蒻刚学了线段树优化建树，想拿这道题练手（我知道可以不用这个做），但是写挂了，检查数据发现是数组没清空全，但不知道哪个部分挂了，有没有会vscode debug的大佬看一下

Problem

#include <bits/stdc++.h>
#define int long long
using namespace std;
template<typename T>
T read(T x)
{
    T opt = 1, sum = 0;
    char ch = getchar();
    while(!isdigit(ch)) opt = (ch == '-') ? -1 : 1, ch = getchar();
    while( isdigit(ch)) sum = (sum << 1) + (sum << 3) + (ch ^ 48), ch = getchar();
    return opt * sum;
}
#define read read(0ll)
const int N = 1e5 + 5;
int T = 5e5;
struct node
{
	int l, r;
}tr[N << 3];
int leaf[N];
struct Edge{int v, w;};
vector<Edge> g[N << 3];
bool vis[N << 3];
struct NM
{
	int l, r, real;
	bool operator<(const NM& other) const {
        return real < other.real;
    }
}a[N];
vector<int> cun; 
void build(int u, int l, int r){
	tr[u].l = l, tr[u].r = r;
	if(l == r) {
		leaf[l] = u;
		return ;
	}
	int mid = (l + r) / 2;
	g[u].push_back({u << 1, 0});
	g[u].push_back({u << 1 | 1, 0});
	g[(u << 1) + T].push_back({u + T, 0});
	g[(u << 1 | 1) + T].push_back({u + T, 0});
	build(u << 1, l, mid), build(u << 1 | 1, mid + 1, r);
}
void goclear(int u, int l, int r){
	tr[u].l = 0, tr[u].r = 0;
	if(l == r) {
		return ;
	}
	int mid = (l + r) / 2;
	g[u].clear();
	g[(u << 1) + T].clear();
	g[(u << 1 | 1) + T].clear();
	goclear(u << 1, l, mid), goclear(u << 1 | 1, mid + 1, r);
}
void update(int u, int l, int r, int v, int w, int op){
	if(l <= tr[u].l && tr[u].r <= r){
		if(op) { // [l, r] -> v
			g[u + T].push_back({v, w});
		}
		else g[v].push_back({u, w}), cun.push_back(v);
		return;
	}
	int mid = (tr[u].l + tr[u].r) / 2;
	if(r <= mid) update(u << 1, l, r, v, w, op);
	else if(l > mid) update(u << 1 | 1, l, r, v, w, op);
	else update(u << 1, l, mid, v, w, op), update(u << 1 | 1, mid + 1,r, v, w, op);
}

int aans = INT_MIN;
void dfs(int u){
//    cout << u << endl;
	vis[u] = 1;
	aans = max(aans, a[u].real);
	for(int i = 0;i < g[u].size();i ++ ){
		int v = g[u][i].v;
		if(v == u || vis[v]) continue;
		dfs(v);
	}
} 
void work()
{
	memset(vis, 0, sizeof(vis)), memset(leaf, 0, sizeof(leaf)); 
	int n = read, k = read; aans = k;

	for(int i = 1;i <= n;i ++ ) vis[i] = leaf[i] = a[i].l = a[i].r = a[i].real = 0;
	for(int i = 1;i <= n;i ++ ){
		int l = read, r = read, real = read;
		a[i] = {l, r, real};
	}
	build(1, 1, n);
	sort(a + 1, a + 1 + n);
	for(int i = 1;i <= n;i ++ ){
		int l = lower_bound(a + 1, a + 1 + n, NM{0, 0, a[i].l}) - a;
		int r = upper_bound(a + 1, a + 1 + n, NM{0, 0, a[i].r}) - a - 1;
		if(l > r) continue;
		l = max((int)1, l), r = min(r, n); 
		update(1, l, r, leaf[i], 1, 0);
	}
	for(int i = 1;i <= n;i ++ ) g[leaf[i] + T].push_back({leaf[i], 0}), g[leaf[i]].push_back({leaf[i] + T, 0});
	for(int i = 1;i <= n;i ++ ){
		if(a[i].l <= k && k <= a[i].r && !vis[i]){
			dfs(i);
		}
	}
		goclear(1, 1, n);
	for(int i = 1;i <= n;i ++ ) g[leaf[i]].clear(), g[leaf[i] + T].clear();
	for(int i = 0;i < cun.size();i ++ ) g[cun[i]].clear();
	cun.clear();
	cout << aans << endl;
}
signed main(){int T;cin >> T;while(T -- ) work();
}