记录

蒟蒻实在调不通代码了。往大佬指点指点。

样例能过，但代码上来就给我拉了坨大的：一个点没过！

#include <algorithm>
#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
unsigned long long a[5000005] = {}, b[5000005] = {};

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int T;
    cin >> T;
    while (T --) {
        int n, m, t;
        unsigned long long res = 0;
        cin >> n >> m;
        for (int i = 1; i <= n; i ++) {
            cin >> a[i];
        }
        for (int i = 1; i <= m; i ++) {
            cin >> b[i];
        }
        for (int i = 1, j = 1; i <= n && j <= m; i ++) {
            t = j;
            while (a[i] == b[j] && j <= m) {
                j ++;
            }
            res ^= j - t;
        }
        cout << res << '\n';
    }
    return 0;
}