HDU 3074.Multiply game-区间乘法-线段树(单点更新、区间查询)，上推标记取模

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原文链接：http://www.cnblogs.com/ZERO-/p/10679817.html

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#java

本文介绍了一个名为Multiplygame的问题，通过使用线段树数据结构解决区间乘法和单点更新操作。文章提供了详细的代码实现，展示了如何在给定序列上进行区间乘法查询和单点修改，并通过模运算处理大数问题。

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Multiply game

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 3224 Accepted Submission(s): 1173

Problem Description

Tired of playing computer games, alpc23 is planning to play a game on numbers. Because plus and subtraction is too easy for this gay, he wants to do some multiplication in a number sequence. After playing it a few times, he has found it is also too boring. So he plan to do a more challenge job: he wants to change several numbers in this sequence and also work out the multiplication of all the number in a subsequence of the whole sequence.
To be a friend of this gay, you have been invented by him to play this interesting game with him. Of course, you need to work out the answers faster than him to get a free lunch, He he…

Input

The first line is the number of case T (T<=10).
For each test case, the first line is the length of sequence n (n<=50000), the second line has n numbers, they are the initial n numbers of the sequence a1,a2, …,an,
Then the third line is the number of operation q (q<=50000), from the fourth line to the q+3 line are the description of the q operations. They are the one of the two forms:
0 k1 k2; you need to work out the multiplication of the subsequence from k1 to k2, inclusive. (1<=k1<=k2<=n)
1 k p; the kth number of the sequence has been change to p. (1<=k<=n)
You can assume that all the numbers before and after the replacement are no larger than 1 million.

Output

For each of the first operation, you need to output the answer of multiplication in each line, because the answer can be very large, so can only output the answer after mod 1000000007.

Sample Input

1 6 1 2 4 5 6 3 3 0 2 5 1 3 7 0 2 5

Sample Output

240 420

Source

2009 Multi-University Training Contest 17 - Host by NUDT

没什么好说的，水题。

代码:

 1 //HDU 3074.Multiply game-区间乘法-线段树(单点更新+区间查询)
 2 #include<bits/stdc++.h>
 3 using namespace std;
 4 typedef long long ll;
 5 const int maxn=5e5+10;
 6 const ll mod=1000000007;
 7 #define lson l,m,rt<<1
 8 #define rson m+1,r,rt<<1|1
 9 
10 ll tree[maxn<<2];
11 
12 ll pushup(int rt)
13 {
14     tree[rt]=(tree[rt<<1]*tree[rt<<1|1])%mod;
15 }
16 
17 void build(int l,int r,int rt)
18 {
19     if(l==r){
20         scanf("%lld",&tree[rt]);
21         return ;
22     }
23 
24     int m=(l+r)>>1;
25     build(lson);
26     build(rson);
27     pushup(rt);
28 }
29 
30 void update(int pos,ll c,int l,int r,int rt)
31 {
32     if(l==r){
33         tree[rt]=c;
34         return ;
35     }
36 
37     int m=(l+r)>>1;
38     if(pos<=m) update(pos,c,lson);
39     if(pos> m) update(pos,c,rson);
40     pushup(rt);
41 }
42 
43 ll query(int L,int R,int l,int r,int rt)
44 {
45     if(L>r||l>R) return 0;
46     if(L<=l&&r<=R){
47         return tree[rt];
48     }
49 
50     int m=(l+r)>>1;
51     ll ret=1;
52     if(L<=m) ret=(ret*query(L,R,lson))%mod;
53     if(R> m) ret=(ret*query(L,R,rson))%mod;
54     return ret;
55 }
56 
57 int main()
58 {
59     int t;
60     scanf("%d",&t);
61     while(t--){
62         int n;
63         scanf("%d",&n);
64         build(1,n,1);
65         int m;
66         scanf("%d",&m);
67         for(int i=1;i<=m;i++){
68             int op;
69             scanf("%d",&op);
70             if(op==0){
71                 int l,r;
72                 scanf("%d%d",&l,&r);
73                 printf("%lld\n",query(l,r,1,n,1));
74             }
75             else{
76                 int pos;ll val;
77                 scanf("%d%lld",&pos,&val);
78                 val=val%mod;
79                 update(pos,val,1,n,1);
80             }
81         }
82     }
83 }