蒟蒻求助莫队20pts

#include <iostream>
#include <algorithm>
#include <cmath>
const int sz = 1e5 + 10;
int arr[sz], xarr[sz << 1], cxarr[sz << 1], cnt[sz << 1], npp, qpp, tpp, ans[sz];
struct query {
    int l, r, id, bl, br, t, num;
    bool operator<(const query &a) const {
        if (bl != a.bl) return l < a.l;
        if (br != a.br) {
            if (bl & 1) return r < a.r;
            return r > a.r;
        }
        if (br & 1) return t < a.t;
        return t > a.t;
    }
} que[sz];
struct modify {
    int pos, val;
} change[sz];
void Change(int t, int ln, int rn) {
    int pos = change[t].pos, &val = change[t].val;
    if (pos >= ln && pos <= rn) cnt[arr[pos]]--, cnt[val]++;
    std::swap(arr[pos], val);
}
int main() {
    std::ios::sync_with_stdio(false);
    int n, q;
    std::cin >> n >> q;
    int lim = std::pow(n, 2. / 3.);
    for (int i = 1; i <= n; i++) std::cin >> arr[i], xarr[++npp] = arr[i];
    for (int i = 1; i <= n; i++) {
        char op;
        int x, y, val;
        std::cin >> op >> x >> y;
        if (op == 'Q')
            std::cin >> val, que[++qpp] = query{x, y, qpp, (x - 1) / lim + 1, (y - 1) / lim + 1, tpp, val}, xarr[++npp] = val;
        else change[++tpp] = modify{x, y}, xarr[++npp] = y;
    }
    std::sort(que + 1, que + qpp + 1);
    std::copy(xarr + 1, xarr + npp + 1, cxarr + 1);
    int f = std::unique(cxarr + 1, cxarr + npp + 1) - cxarr;
    for (int i = 1; i <= n; i++)
        arr[i] = std::lower_bound(cxarr + 1, cxarr + f, arr[i]) - cxarr;
    for (int i = 1; i <= qpp; i++)
        que[i].num = std::lower_bound(cxarr + 1, cxarr + f, que[i].num) - cxarr;
    for (int i = 1; i <= tpp; i++)
        change[i].val = std::lower_bound(cxarr + 1, cxarr + f, change[i].val) - cxarr;
    auto add = [](int x) { cnt[arr[x]]++; };
    auto del = [](int x) { cnt[arr[x]]--; };
    int l = 1, r = 0, t = 0;
    for (int i = 1; i <= qpp; i++) {
        int le = que[i].l, re = que[i].r, te = que[i].t;
        while (l > le) add(--l);
        while (r < re) add(++r);
        while (l < le) del(l++);
        while (r > re) del(r--);
        while (t < te) Change(++t, le, re);
        while (t > te) Change(t--, le, re);
        ans[que[i].id] = cnt[que[i].num];
    }
    for (int i = 1; i <= qpp; i++)
        std::cout << ans[i] << "\n";
    return 0;
}