1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
| #include <bits/stdc++.h>
#define ll long long
#define IOS {ios::sync_with_stdio(false);cin.tie(0);}
using namespace std;
const int maxn = 200000 + 5;
ll N, M, a[maxn], d[maxn << 2];
int _a, _b;
char ch;
void push_up(int p)
{
d[p] = max(d[p << 1], d[p << 1 |1]);
}
void build(int l, int r, int p)
{
if(l == r)
d[p] = a[l];
else
{
int m = (l + r) >> 1;
build(l, m, p << 1);
build(m + 1, r, p << 1 | 1);
push_up(p);
}
}
void update(int x, int v, int l, int r, int p)
{
if(l == r)
d[p] = v;
else
{
int m = (l + r) >> 1;
if(x <= m)
update(x, v, l, m, p << 1);
else
update(x, v, m + 1, r, p << 1 | 1);
push_up(p);
}
}
int query(int L, int R, int l, int r, int p)
{
if(L <= l && R >= r)
return d[p];
int ans = 0;
int m = (l + r) >> 1;
if(L <= m)
{
ans = max(ans, query(L, R, l, m, p << 1));
}
if(R > m)
{
ans = max(ans, query(L, R, m + 1, r, p << 1 | 1));
}
return ans;
}
int main(void)
{
IOS
while(cin >> N >> M)
{
memset(a, 0, sizeof(a));
memset(d, 0, sizeof(d));
for(int i = 1; i <= N; i++)
{
cin >> a[i];
}
build(1, N, 1);
while(M--)
{
cin >> ch;
if(ch == 'Q')
{
cin >> _a >> _b;
cout << query(_a, _b, 1, N, 1) << endl;
}
else if(ch == 'U')
{
cin >> _a >> _b;
update(_a, _b, 1, N, 1);
}
}
}
return 0;
}
|
