1 #include <iostream>
2 #include <cstdio>
3 #include <algorithm>
4 #include <cstring>
5 #include <cmath>
6 #define ll long long
7 using namespace std;
8
9 template <typename T> void in(T &x) {
10 x = 0; T f = 1; char ch = getchar();
11 while(!isdigit(ch)) {if(ch == '-') f = -1; ch = getchar();}
12 while(isdigit(ch)) {x = 10*x + ch - '0'; ch = getchar();}
13 x *= f;
14 }
15
16 template <typename T> void out(T x) {
17 if(x < 0) putchar('-'),x = -x;
18 if(x > 9) out(x/10);
19 putchar(x%10 + '0');
20 }
21
22 //------------------------------------------------------------
23
24 const int N = 50005;
25
26 int n,q,a;
27
28 struct node {
29 int lm,rm,all,sum;
30 }t[N<<2];
31
32 void P_up(node &u,node ls,node rs) {
33 u.sum = ls.sum + rs.sum;
34 u.all = max(max(ls.all,rs.all),ls.rm+rs.lm);
35 u.lm = max(ls.lm,ls.sum+rs.lm); u.rm = max(rs.rm,rs.sum+ls.rm);
36 u.all = max(u.all,max(u.lm,u.rm));
37 }
38
39 void Build(int u,int l,int r) {
40 if(l == r) {in(a); t[u].lm = t[u].rm = t[u].all = t[u].sum = a; return;}
41 int mid = (l+r)>>1;
42 Build(u<<1,l,mid); Build(u<<1|1,mid+1,r);
43 P_up(t[u],t[u<<1],t[u<<1|1]);
44 }
45
46 void A(int u,int l,int r,int x,int k) {
47 if(l == r) {t[u].all = t[u].lm = t[u].rm = t[u].sum = k; return;}
48 int mid = (l+r)>>1;
49 if(x <= mid) A(u<<1,l,mid,x,k); else A(u<<1|1,mid+1,r,x,k);
50 P_up(t[u],t[u<<1],t[u<<1|1]);
51 }
52
53 node Q(int u,int l,int r,int x,int y) {
54 if(x <= l && y >= r) {return t[u];}//important
55 int mid = (l+r)>>1;
56 if(y <= mid) return Q(u<<1,l,mid,x,y);
57 else if(x > mid) return Q(u<<1|1,mid+1,r,x,y);
58 else {
59 node _u,ls,rs;
60 ls = Q(u<<1,l,mid,x,mid); rs = Q(u<<1|1,mid+1,r,mid+1,y);
61 P_up(_u,ls,rs);
62 return _u;
63 }
64 }
65
66 int main() {
67 int op,x,y; in(n);
68 Build(1,1,n);
69 in(q);
70 while(q--) {
71 in(op); in(x); in(y);
72 if(!op) A(1,1,n,x,y);
73 else out(Q(1,1,n,x,y).all),putchar('\n');
74 }
75 return 0;
76 }
