为啥这个代码会全部 MLE 啊 /kk

#include<bits/stdc++.h>
using namespace std;

#define pb push_back
#define dbg(x) cerr << #x << " = " << x << endl;

template < typename Tp >
inline void rd(Tp &x) {
	x = 0; int fh = 1; char ch = 1;
	while(ch != '-' && (ch < '0' || ch > '9')) ch = getchar();
	if(ch == '-') fh = -1, ch = getchar();
	while(ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
	x *= fh;
}

template < typename Tp >
inline void chrd(Tp &x) {
	char ch = 1;
	while(ch != 'Q' && ch != 'U') ch = getchar();
	if(ch == 'U') x = 1;
	else x = 2;
}
#define int long long
const int mod = 998244353;
template < typename Tp > inline void smax(Tp &x, Tp y) {if(x < y) x = y;}
template < typename Tp > inline void smin(Tp &x, Tp y) {if(x > y) x = y;}
template < typename Tp > inline void chkadd(Tp &x, Tp y) {x = (x + y) % mod;}
template < typename Tp > inline Tp abs(Tp x) {return (x < 0) ? -x : x;}

const int maxn = 1000000 + 7;
const int maxm = 2000000 + 7;

int n, Q;
int Head[maxn], to[maxm], Next[maxm], tot;
int v[maxn];

void add(int x, int y) {
	to[++tot] = y, Next[tot] = Head[x], Head[x] = tot;
}

inline void Init(void) {
	rd(n); rd(Q);
	for(int i = 1; i <= n; i++) rd(v[i]);
	for(int i = 1, x, y; i < n; i++) {
		rd(x); rd(y);
		add(x, y); add(y, x);
	}
}

int size[maxn], son[maxn], top[maxn], dfn[maxn], Pre[maxn], ind;
int fa[maxn], dep[maxn];

void dfs1(int x, int f) {
	dep[x] = dep[f] + 1, fa[x] = f, size[x] = 1;
	int mx = -1;
	for(int i = Head[x]; i; i = Next[i]) {
		int y = to[i];
		if(y == f) continue;
		dfs1(y, x); size[x] += size[y];
		if(size[y] > mx) mx = size[y], son[x] = y;
	}
}

void dfs2(int x, int tp) {
	top[x] = tp, dfn[x] = ++ind, Pre[ind] = x;
	if(!son[x]) return ;
	dfs2(son[x], tp);
	for(int i = Head[x]; i; i = Next[i]) {
		int y = to[i];
		if(y == fa[x] || y == son[x]) return ;
		dfs2(y, y);
	}
}

#define lson (x << 1)
#define rson ((x << 1) | 1)
#define mid ((l + r) >> 1)

int val[maxn << 2], tag[maxn << 2];

void build(int x, int l, int r) {
//	assert(l <= r);
	if(l == r) {val[x] = v[Pre[l]]; return ;}
	build(lson, l, mid); build(rson, mid + 1, r);
}

void modify(int x, int l, int r, int L, int R, int necc) {
//	assert(l <= r); assert(L <= R);
	if(L <= l && r <= R) {tag[x] ^= necc; return ;}
	if(L <= mid) modify(lson, l, mid, L, R, necc);
	if(R > mid) modify(rson, mid + 1, r, L, R, necc);
}

int query(int x, int l, int r, int pos) {
//	assert(l < r);
	if(l == r) return val[x] ^ tag[x];
	int res;
	if(pos <= mid) res = query(lson, l, mid, pos);
	else res = query(rson, mid + 1, r, pos);
	return res ^ tag[x];
}

#undef lson
#undef rson
#undef mid

int d[500];

inline bool insert(int x) {
	for(int i = 30; i >= 0; i--) if((x >> i) & 1){
		if(!d[i]) {d[i] = x; return true;}
		x ^= d[i]; if(!x) return false;
	}
	return true;
}

inline void clear(void) {memset(d, 0, sizeof(d));}

inline int LCA(int x, int y) {
	while(top[x] != top[y]) {
		if(dep[top[x]] < dep[top[y]]) swap(x, y);
		x = fa[top[x]];
	}
	if(dep[x] < dep[y]) return x;
	return y;
}

inline void op1(void) {
	int x, y, z; rd(x); rd(y); rd(z);
	while(top[x] != top[y]) {
		if(dep[top[x]] < dep[top[y]]) swap(x, y);
		modify(1, 1, n, dfn[top[x]], dfn[x], z);
		x = fa[x];
	}
	if(dep[x] > dep[y]) swap(x, y);
	modify(1, 1, n, dfn[x], dfn[y], z);
}

inline void op2(void) {
	int x, y; rd(x); rd(y);
	int lca = LCA(x, y);
	clear();
	if(dep[x] + dep[y] - 2 * dep[lca] + 1 >= 31) {
		puts("YES"); return ;
	}
	while(x != lca) {
		if(!insert(query(1, 1, n, dfn[x]))) {
			puts("YES"); return ;
		}
		x = fa[x];
	}
	while(y != lca) {
		if(!insert(query(1, 1, n, dfn[y]))) {
			puts("YES"); return ;
		}
		y = fa[y];
	}
	if(!insert(query(1, 1, n, dfn[lca]))) puts("YES");
	else puts("NO");
//	printf("%d\n", query(1, 1, n, 1));
//	printf("%d\n", query(1, 1, n, 2));
}

inline void Work(void) {
	dfs1(1, 0); dfs2(1, 1);
	build(1, 1, n);
	while(Q--) {
		string sl; cin >> sl;
//		int op; chrd(op);
		if(sl[0] == 'U') op1();
		else op2();
	}
}

signed main(void) {
	Init();
	Work();
	return 0;
}