Number of Minimums on a Segment，Wrong answer on test 12，求 Hack，thx.

#include <bits/stdc++.h>

std::vector<int> a, min, cnt;

int ls(int p) { return (p << 1) + 1; }

int rs(int p) { return (p << 1) + 2; }

void build(int l, int r, int p = 0) {
    if (l == r) {
        min.at(p) = a.at(l);
        cnt.at(p) = 1;
    } else {
        const int mid = l + r >> 1;
        build(l, mid, ls(p));
        build(mid + 1, r, rs(p));
        const int lm = min.at(ls(p)), rm = min.at(rs(p));
        if (lm == rm) {
            min.at(p) = lm;
            cnt.at(p) = cnt.at(ls(p)) + cnt.at(rs(p));
        } else if (lm < rm) {
            min.at(p) = lm;
            cnt.at(p) = cnt.at(ls(p));
        } else {
            min.at(p) = rm;
            cnt.at(p) = cnt.at(rs(p));
        }
    }
}

int mfind(int l, int r, int pl, int pr, int p = 0) {
    if (l <= pl && r >= pr)
        return min.at(p);
    const int mid = pl + pr >> 1;
    if (l <= mid && r > mid)
        return std::min(mfind(l, r, pl, mid, ls(p)), mfind(l, r, mid + 1, pr, rs(p)));
    else if (l <= mid)
        return mfind(l, r, pl, mid, ls(p));
    else
        return mfind(l, r, mid + 1, pr, rs(p));
}

int cfind(int l, int r, int pl, int pr, int p = 0) {
    if (l <= pl && r >= pr)
        return cnt.at(p);
    const int mid = pl + pr >> 1;
    if (l <= mid && r > mid)
        return cfind(l, r, pl, mid, ls(p)) + cfind(l, r, mid + 1, pr, rs(p));
    else if (l <= mid)
        return cfind(l, r, pl, mid, ls(p));
    else
        return cfind(l, r, mid + 1, pr, rs(p));
}

void modify(int idx, int v, int pl, int pr, int p = 0) {
    if (pl == pr) {
        a.at(idx) = v;
        min.at(p) = v;
    } else {
        int mid = pl + pr >> 1;
        if (idx <= mid)
            modify(idx, v, pl, mid, ls(p));
        else
            modify(idx, v, mid + 1, pr, rs(p));
        const int lm = min.at(ls(p)), rm = min.at(rs(p));
        if (lm == rm) {
            min.at(p) = lm;
            cnt.at(p) = cnt.at(ls(p)) + cnt.at(rs(p));
        } else if (lm < rm) {
            min.at(p) = lm;
            cnt.at(p) = cnt.at(ls(p));
        } else {
            min.at(p) = rm;
            cnt.at(p) = cnt.at(rs(p));
        }
    }
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int n, m;
    std::cin >> n >> m;
    a.resize(n);
    min.resize(n << 2);
    cnt.resize(n << 2);
    for (int &v : a)
        std::cin >> v;
    build(0, n - 1);
    while (m--) {
        int tp, x, y;
        std::cin >> tp >> x >> y;
        if (tp == 1)
            modify(x, y, 0, n - 1);
        else
            std::cout << mfind(x, y - 1, 0, n - 1) << ' ' << cfind(x, y - 1, 0, n - 1) << '\n';
    }

    return 0;
}