TLE求调

#include<iostream>
#include <algorithm>
#include<cstring>
#include <vector>
using namespace std;
unsigned long long a[10000001];
unsigned long long b[10000001];
int main() {
	int t;
	cin >> t;
	for (int i = 1; i <= t; i++) {
		int ans = 0;
		int n, m;
		cin >> n >> m;
		for (int j = 1; j <= n; j++) {
			cin >> a[j];
		}
		for (int j = 1; j <= m; j++) {
			cin >> b[j];
		}
		int low = 1;
		int high = 1;
		int cnt = 0;
		while (low <= n&&high<=m) {
			if (a[low] == b[high]) {
				high++;
				cnt++;
			}
			else
			{
				low++;
				if (cnt != 0) {
					ans = ans ^ cnt;
				}
				cnt = 0;
			}
		}
		for (int j = 1; j <= n; j++) {
			a[j]=0;
		}
		for (int j = 1; j <= m; j++) {
			b[i] = 0;
		}
		cout << ans << endl;
	}
}