摆烂之在学校不好好上课

#include<iostream>
#include<cstdio>
#define int long long
using namespace std;

const int N=2e5+7,M=N*4;

int n,q;
int a[N],b[N];

struct Node
{
    int l,r;
    int pre,ll;//pre-->区间的第一个数 ll-->最长非递减前缀
    int last,lr;//last-->区间最后一个数 lr-->最长非递减后缀
    int ans;
    void init(int _)
    {
        pre=last=_;
        ans=ll=lr=1;
    }
}tr[M];

void pushup(Node &t,Node &left,Node &right)
{
    t.ans=left.ans+right.ans;
    t.pre=left.pre,t.last=right.last;
    t.ll=left.ll,t.lr=right.lr;
    if(right.pre>=left.last)
    {
        int x=left.r-left.l+1;
        int y=right.r-right.l+1;
        t.ans+=right.ll*left.lr;
        if(x==left.lr)t.ll=x+right.ll;
        if(y==right.ll)t.lr=y+left.lr;
    }
}

void pushup(int u)
{
    pushup(tr[u],tr[u<<1],tr[u<<1|1]);
}

void build(int u,int l,int r)
{
    tr[u].l=l,tr[u].r=r;
    if(l==r)
    {
        tr[u].init(a[l]);
        return;
    }
    int mid=l+r>>1;
    build(u<<1,l,mid),build(u<<1|1,mid+1,r);
    pushup(u);
}

void modify(int u,int x,int y)
{
    if(tr[u].l==x&&tr[u].r==x)
    {
        tr[u].init(y);
    }
    else
    {
        int mid=tr[u].l+tr[u].r>>1;
        if(x<=mid)modify(u<<1,x,y);
        else modify(u<<1|1,x,y);
        pushup(u);
    }
}

Node query(int u,int l,int r)
{
    if(tr[u].l>=l&&tr[u].r<=r)return tr[u];
    else
    {
        int mid=tr[u].l+tr[u].r>>1;
        if(r<=mid)return query(u<<1,l,r);
        else if(l>mid)return query(u<<1|1,l,r);
        else
        {
            Node left=query(u<<1,l,r);
            Node right=query(u<<1|1,l,r);
            Node res;
            pushup(res,left,right);
            return res;
        }
    }
}

signed main()
{
    scanf("%lld%lld",&n,&q);
    for(int i=1;i<=n;i++)scanf("%lld",&a[i]);
    build(1,1,n);
    while(q--)
    {
        int op,x,y;
        scanf("%lld%lld%lld",&op,&x,&y);
        if(op==1) modify(1,x,y);
        else printf("%lld\n",query(1,x,y).ans);
    }
    return 0;
}