9pts WA求助，样例过了

#include<bits/stdc++.h>
#define int long long 
using namespace std;
const int N = 1e5 + 9,ROOT = 1,INF = 1e9 + 9;
int a[N];
struct seg_tree{
    struct node {
        int val,sum,lsum,rsum,change;
    } tree[N << 2];
    bool in_range(int l,int r,int now_l,int now_r){
        return l <= now_l && now_r <= r;
    }
    bool out_range(int l,int r,int now_l,int now_r){
        return now_r < l || now_l > r;
    }
    int len(int l,int r){
        return r - l + 1;
    }
    void push_up(int root){
        int lchild = root * 2,rchild = root * 2 + 1;
        tree[root].sum = tree[lchild].sum + tree[rchild].sum;
        tree[root].val = max(max(tree[lchild].val,tree[rchild].val),tree[lchild].rsum + tree[rchild].lsum);
        tree[root].lsum = max(tree[lchild].lsum,tree[lchild].sum + tree[rchild].lsum);
        tree[root].rsum = max(tree[rchild].rsum,tree[rchild].sum + tree[lchild].rsum);
    }
    void make_tag(int Len,int root,int change){
        tree[root].change = change;
        tree[root].val = tree[root].sum = tree[root].lsum = tree[root].rsum = Len * change;
    }
    void push_down(int l,int r,int root){
        int mid = (l + r) / 2,lchild = root * 2,rchild = root * 2 + 1;
        if(tree[root].change != INF){
            make_tag(len(l,mid),lchild,tree[root].change);
            make_tag(len(mid + 1,r),rchild,tree[root].change);
            tree[root].change = INF;
        }
    }
    void build(int l,int r,int root) {
        tree[root].change = INF;
        if(l == r) {
            tree[root].val = tree[root].sum = tree[root].lsum = tree[root].rsum = a[l];
            return;
        }
        int mid = (l + r) / 2,lchild = root * 2,rchild = root * 2 + 1;
        build(l,mid,lchild);
        build(mid + 1,r,rchild);
        push_up(root);
    }
    void update(int l,int r,int now_l,int now_r,int root,int change) {
        if(in_range(l,r,now_l,now_r))
            make_tag(len(l,r),root,change);
        else if(!out_range(l,r,now_l,now_r)){
            int mid = (now_l + now_r) / 2,lchild = root * 2,rchild = root * 2 + 1;
            push_down(now_l,now_r,root);
            update(l,r,mid + 1,now_r,rchild,change);
            update(l,r,now_l,mid,lchild,change);
            push_up(root);
        }
        return;
    }
    int getsum(int l, int r, int now_l, int now_r, int root) {
        int mid = (now_l + now_r) / 2,lchild = root * 2,rchild = root * 2 + 1;
        if(in_range(l,r,now_l,now_r))
            return tree[root].val;
        else if(!out_range(l,r,now_l,now_r)){
            push_down(now_l,now_r,root);
            return max(getsum(l,r,now_l,mid,lchild),getsum(l,r,mid + 1,now_r,rchild));
        }
        else
            return -INF;
    }
} seg;
int n,m;
int op,x,y,k;
signed main() {
    scanf("%lld%lld", &n, &m);
    for(int i = 1; i <= n; i++)
        scanf("%lld", &a[i]);
    seg.build(1,n,ROOT);
    for(int i = 1; i <= m; i++) {
        scanf("%lld%lld%lld", &op, &x, &y);
        if(op == 1){
            if(x > y)
                swap(x,y);
            printf("%lld\n",seg.getsum(x,y,1,n,ROOT));
        }
        else
            seg.update(x,x,1,n,ROOT,y);
    }
}