[模板] 线性基

[模板] 线性基

const int M = 61;

ll a[M + 1], tmp[M + 1];
bool flag;  //判断0

void ins(ll x) {
    for (int i = M; i >= 0; i--)
        if (x & (1ll << i))
            if (!a[i]) { a[i] = x; return; }
            else x ^= a[i];
    flag = true;
}

bool check(ll x) {   //能否表示出x
    for (int i = M; i >= 0; i--)
        if (x & (1ll << i))
            if (!a[i]) return false;
            else x ^= a[i];
    return true;
}

ll qmax() {
    ll res = 0;
    for (int i = M; i >= 0; i--)
        res = max(res, res ^ a[i]);
    return res;
}

ll qmin() {
    if (flag) return 0;
    for (int i = 0; i <= M; i++)
        if (a[i]) return a[i];
}

ll query(ll k) {   //第k小
    ll res = 0;
    int cnt = 0;
    k -= flag;
    if (!k) return 0;
    for (int i = 0; i <= M; i++) {
        for (int j = i - 1; j >= 0; j--)
            if (a[i] & (1ll << j)) a[i] ^= a[j];
        if (a[i]) tmp[cnt++] = a[i];
    }
    if (k >= (1ll << cnt)) return -1;
    for (int i = 0; i < cnt; i++)
        if (k & (1ll << i)) res ^= tmp[i];
    return res;
}