SQRT-decomposition with add/del/get operations

int sz[N];
vector <pii> mn[N];
vector <vector <pii>> g[N];
void fill_v(int id, int block) {
    while (sz(g[id]) <= block)g[id].pb({});
    while (sz(mn[id]) <= block)mn[id].pb({inf, inf});
}
void build(int id) {
    vector <pii> vec;
    for (int block = 0;block < sz(g[id]);block++) {
        for (auto val : g[id][block])vec.pb(val);
    }
    g[id].clear(), mn[id].clear();
    for (int i = 0;i < sz(vec);i++) {
        int block = i / K;
        fill_v(id, block);
        g[id][block].pb(vec[i]);
        if (i % K == 0)mn[id].pb(vec[i]);
    }
}
bool bigger(pii val, pii x) {
    return (val.x > x.x) || (val.x == x.x && val.y >= x.y);
}
pii get(pii val, int id) {
    int b = 0;
    fill_v(id, b + 1);
    while (b + 1 < sz(mn[id]) && bigger(val, mn[id][b + 1]))b++;
    int pos = 0;
    while (pos < sz(g[id][b]) && bigger(val, g[id][b][pos]))pos++;
    return {b, pos};
}
void add(pii val, int id) {
    int block, pos;
    tie(block, pos) = get(val, id);
    vector <pii> vals;
    fill_v(id, block);
    int cnt = sz(g[id][block]) - pos;
    while (cnt--)vals.pb(g[id][block].back()), g[id][block].pop_back();
    mn[id][block] = min(mn[id][block], val);
    g[id][block].pb(val), sz[id]++;
    while (!vals.empty())g[id][block].pb(vals.back()), vals.pop_back();
    if (sz(g[id][block]) > 2 * K)build(id);
}
void del(pii val, int id) {
    int block, pos;
    tie(block, pos) = get(val, id);
    vector <pii> vals;
    fill_v(id, block);
    int cnt = sz(g[id][block]) - pos;
    while (cnt--)vals.pb(g[id][block].back()), g[id][block].pop_back();
    if (!g[id][block].empty())g[id][block].pop_back(), sz[id]--;
    while (!vals.empty())g[id][block].pb(vals.back()), vals.pop_back();
    if (sz(g[id][block]) == 0)build(id);
}