题解 | 锁

注意：X 可能会大于 Y！！！

#include <bits/stdc++.h>

using namespace std;

int main() {
    int T;
    cin >> T;
    while (T--) {
        int n, m, x, y;
        map<int, int> mp;
        cin >> n >> m >> x >> y;
        int ans1 = x, ans2 = n - y + 1;
        for (int i = 0; i < m; i++) {
            int p;
            cin >> p;
            if (mp[p] == 0) {
                mp[p] = 1;
                if (p <= x) ans1--;
                if (p >= y) ans2--;
            }
            else {
                mp[p] = 0;
                if (p <= x) ans1++;
                if (p >= y) ans2++;
            }
            cout << ans1 << ' ' << ans2 << '\n';
        }
    }
    return 0;
}