1 #include<stdio.h>
 2 #include<string.h>
 3 #define lson root<<1,l,mid
 4 #define rson root<<1|1,mid+1,r
 5 const int MAXN=200010<<2;
 6 #define X int root,int l,int r
 7 #define Y 1,1,N
 8 #define MAX(x,y)(x>y?x:y)
 9 #define NOW tree[root]=MAX(tree[root<<1],tree[root<<1|1])
10 int tree[MAXN];
11 int A,B,anser;
12 void build(X){
13     if(l==r)scanf("%d",&tree[root]);
14     else {
15         int mid=(l+r)>>1;
16         build(lson);
17         build(rson);
18         NOW;
19     }
20 }
21 void update(X){
22     if(l==A&&r==A)tree[root]=B;
23     else{
24         int mid=(l+r)>>1;
25         if(A<=mid)update(lson);
26         else update(rson);
27         NOW;
28     }
29 }
30 void print(X){
31     if(A<=l&&B>=r)anser=MAX(anser,tree[root]);//这个是从线段树的顶往下搜的
32     else{
33         int mid=(l+r)>>1;
34         if(A<=mid)print(lson);//记住mid
35         if(B>mid)print(rson);
36         NOW;
37     }
38 }
39 int main(){
40     int N,M;
41     char s[2];
42     while(~scanf("%d%d",&N,&M)){
43         build(Y);
44         while(M--){
45             scanf("%s",s);
46         if(!strcmp(s,"U")){
47             scanf("%d%d",&A,&B);
48             update(Y);
49         }
50         else{
51             anser=0;
52             scanf("%d%d",&A,&B);
53             print(Y);
54             printf("%d\n",anser);
55         }
56         }
57     }
58     return 0;
59 }

 1 #include<algorithm>
 2 using namespace std;
 3 #include<stdio.h>
 4 #include<string.h>
 5 const int INF=0x3f3f3f3f;
 6 const int MAXN=200010;
 7 #define lson root<<1,l,mid
 8 #define rson root<<1|1,mid+1,r
 9 #define L tree[root].l
10 #define R tree[root].r
11 #define V tree[root].v
12 #define NOW tree[root].v=MAX(tree[root<<1].v,tree[root<<1|1].v)
13 //#define LOCAL
14 int MAX(int x,int y){
15     return x>y?x:y;
16 }
17 struct Node{
18     int l,r,v;
19 };
20 Node tree[MAXN<<2];
21 int ans;
22 void build(int root,int l,int r){
23     L=l;R=r;
24     if(l==r){
25         scanf("%d",&V);
26     }
27     else{
28         int mid=(l+r)>>1;
29         build(lson);
30         build(rson);
31         NOW;
32     }
33 }
34 void update(int root,int x,int y){
35     if(L==x&&R==x){
36         V=y;
37     }
38     else{
39         int mid=(L+R)>>1;
40         if(mid>=x)update(root<<1,x,y);
41         else update(root<<1|1,x,y);
42         NOW;
43     }
44 }
45 void query(int root,int x,int y){
46     if(L>=x&&R<=y){
47         ans=MAX(ans,V);
48     }
49     else {
50         int mid=(L+R)>>1;
51         if(mid>=x)query(root<<1,x,y);
52         if(mid<y)query(root<<1|1,x,y);
53     }
54 }
55 int main(){
56     #ifdef LOCAL
57     freopen("data.in","r",stdin);
58     freopen("data.out","w",stdout);
59     #endif
60     int N,M;
61     char s[5];
62     int a,b;
63     while(~scanf("%d%d",&N,&M)){
64         build(1,1,N);
65         while(M--){
66         scanf("%s%d%d",s,&a,&b);
67         if(s[0]=='U'){
68             update(1,a,b);
69         }
70         else{
71             ans=0;
72             if(a>b)swap(a,b);
73             query(1,a,b);
74             printf("%d\n",ans);
75             }
76         }
77     }
78     return 0;
79 }