[模板]线段树动态维护区间最大最小值 标程

#include <bits/stdc++.h>
using namespace std;
#define ll p * 2
#define rr p * 2 + 1
const int maxn = 1e6 + 10;
class edge
{
public:
    int l, r, add, min = 0x3f3f3f3f, max = -0x3f3f3f3f;
} tree[maxn];
int a[maxn];
void build(int p, int l, int r)
{
    tree[p].l = l, tree[p].r = r;
    if (l == r)
    {
        tree[p].min = tree[p].max = a[l];
        return;
    }
    int mid = (l + r) / 2;
    build(ll, l, mid);
    build(rr, mid + 1, r);
    tree[p].min = min(tree[ll].min, tree[rr].min);
    tree[p].max = max(tree[ll].max, tree[rr].max);
    return;
}
void spread(int p)
{
    if (tree[p].add)
    {
        tree[ll].add += tree[p].add, tree[rr].add += tree[p].add;
        tree[ll].max += tree[p].add, tree[ll].min += tree[p].add;
        tree[rr].max += tree[p].add, tree[rr].min += tree[p].add;
        tree[p].add = 0;
    }
    return;
}
void add(int p, int l, int r, int k)
{
    if (l <= tree[p].l && tree[p].r <= r)
    {
        tree[p].add += k;
        tree[p].max += k;
        tree[p].min += k;
        return;
    }
    int mid = (tree[p].r + tree[p].l) / 2;
    spread(p);
    if (l <= mid)
        add(ll, l, r, k);
    if (r >= mid + 1)
        add(rr, l, r, k);
    tree[p].min = min(tree[ll].min, tree[rr].min);
    tree[p].max = max(tree[ll].max, tree[rr].max);
    return;
}
int ask_max(int p, int l, int r)
{
    if (l <= tree[p].l && tree[p].r <= r)
        return tree[p].max;
    int ans = -0x3f3f3f3f;
    int mid = (tree[p].l + tree[p].r) / 2;
    spread(p);
    if (l <= mid)
        ans = max(ans, ask_max(ll, l, r));
    if (r >= mid + 1)
        ans = max(ans, ask_max(rr, l, r));
    return ans;
}
int ask_min(int p, int l, int r)
{
    if (l <= tree[p].l && tree[p].r <= r)
        return tree[p].min;
    int ans = 0x3f3f3f3f;
    int mid = (tree[p].l + tree[p].r) / 2;
    spread(p);
    if (l <= mid)
        ans = min(ans, ask_min(ll, l, r));
    if (r >= mid + 1)
        ans = min(ans, ask_min(rr, l, r));
    return ans;
}
int n, m;
int main()
{
    scanf("%d%d", &n, &m);
    for (int i = 1; i <= n; i++)
        scanf("%d", &a[i]);
    build(1, 1, n);
    for (int i = 1; i <= m; i++)
    {
        int num, x, y, z;
        scanf("%d", &num);
        if (num == 1)
        {
            scanf("%d%d%d", &x, &y, &z);
            add(1, x, y, z);
        }
        if (num == 2)
        {
            scanf("%d%d", &x, &y);
            printf("%d\n", ask_max(1, x, y));
        }
        if (num == 3)
        {
            scanf("%d%d", &x, &y);
            printf("%d\n", ask_min(1, x, y));
        }
    }
    return 0;
}