18pts蒻籍求救

#include <bits/stdc++.h>
#define INF 0x3f3f3f3f
#define max(x,y) (x>y?x:y)
#define min(x,y) (x<y?x:y)
using namespace std;
using LL = long long;
LL const N = 3e5 + 5;
LL const LOG = 24;
struct TrieTree {
	struct PoLL {
		LL son[2];
		LL l = INF, r = -INF;
	} AC[N * LOG];
	LL cnt;
	TrieTree() {
		cnt = 1;
	}
	using C_T = LL const&;
	void insert(C_T val, C_T id) {
		LL x = 1;
		for (LL i = LOG; i >= 0; i--) {
			bool k = val & (1 << i);
			if (!AC[x].son[k])
				AC[x].son[k] = ++cnt;
			AC[x].l = min(AC[x].l, id);
			AC[x].r = max(AC[x].r, id);
			x = AC[x].son[k];
		}
		AC[x].l = min(AC[x].l, id);
		AC[x].r = max(AC[x].r, id);
	}
	LL query(C_T val, C_T l, C_T r) {
		LL x = 1, res = 0;
		for (LL i = LOG; i >= 0; i--) {
			bool k = val & (1 << i);
			LL desired = !k;
			if (AC[x].son[desired]) {
				LL son = AC[x].son[desired];
				if (!(AC[son].r < l || AC[son].l > r)) {
					res |= (1 << i);
					x = son;
					continue;
				}
			}
			if (AC[x].son[k]) {
				LL son = AC[x].son[k];
				if (!(AC[son].r < l || AC[son].l > r)) {
					x = son;
					continue;
				}
			}
			return res;
		}
		return res;
	}
} Tr;
LL w[N];
signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	LL n, m;
	cin >> n >> m;
	w[0] = 0;
	Tr.insert(w[0], 0);
	for (LL i = 1; i <= n; i++) {
		LL a;
		cin >> a;
		w[i] = w[i - 1] ^ a;
		Tr.insert(w[i], i);
	}
	while (m--) {
		char op;
		cin >> op;
		if (op == 'A') {
			LL x;
			cin >> x;
			n++;
			w[n] = w[n - 1] ^ x;
			Tr.insert(w[n], n);
		} else {
			LL l, r, x;
			cin >> l >> r >> x;
			LL target = w[n] ^ x;
			cout << Tr.query(target, l - 1, r - 1) << '\n';
		}
	}
	return 0;
}