洛谷P4891 序列

 1 //minamoto
 2 #include<cstdio>
 3 #include<iostream>
 4 #define mul(a,b) (1ll*a*b%P)
 5 using namespace std;
 6 #define getc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++)
 7 char buf[1<<21],*p1=buf,*p2=buf;
 8 int read(){
 9     #define num ch-‘0‘
10     char ch;bool flag=0;int res;
11     while(!isdigit(ch=getc()))
12     (ch==‘-‘)&&(flag=true);
13     for(res=num;isdigit(ch=getc());res=res*10+num);
14     (flag)&&(res=-res);
15     #undef num
16     return res;
17 }
18 char sr[1<<21],z[20];int C=-1,Z;
19 inline void Ot(){fwrite(sr,1,C+1,stdout),C=-1;}
20 void print(int x){
21     if(C>1<<20)Ot();if(x<0)sr[++C]=45,x=-x;
22     while(z[++Z]=x%10+48,x/=10);
23     while(sr[++C]=z[Z],--Z);sr[++C]=‘\n‘;
24 }
25 const int N=2e5+5,P=1e9+7;
26 int n,m,a[N],b[N],c[N],ans=1;
27 int ksm(int a,int b){
28     int res=1;
29     while(b){
30         if(b&1) res=mul(res,a);
31         a=mul(a,a),b>>=1;
32     }
33     return res;
34 }
35 int main(){
36 //    freopen("testdata.in","r",stdin);
37     n=read(),m=read();
38     for(int i=1;i<=n;++i)
39     a[i]=read(),c[i]=max(c[i-1],a[i]);
40     for(int i=1;i<=n;++i)
41     b[i]=read(),ans=mul(min(b[i],c[i]),ans);
42     while(m--){
43         int op=read(),x=read(),y=read();
44         if(op==1){
45             if(b[x]<c[x]){
46                 ans=mul(ans,ksm(b[x],P-2));
47                 ans=mul(ans,min(y,c[x]));
48             }
49             b[x]=y;
50         }else{
51             a[x]=y;
52             while(c[x]<y&&x<=n){
53                 if(c[x]<b[x]){
54                     ans=mul(ans,ksm(c[x],P-2));
55                     ans=mul(ans,min(y,b[x]));
56                 }c[x++]=y;
57             }
58         }
59         print(ans);
60     }
61     return Ot(),0;
62 }