#include<bits/stdc++.h>
#define lcm(a,b) (a/__gcd(a,b))*b
#define fast ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define ll long long int
#define vi vector<int>
#define vll vector<ll>
#define pb push_back
#define F first
#define S second
#define mp make_pair
//salida rapida "\n"
//DECIMALES fixed<<sp(n)<<x<<endl;
//gcd(a,b)= ax + by
//lCB x&-x
//set.erase(it) - ersases the element present at the required index//auto it = s.find(element)
//set.find(element) - iterator pointing to the given element if it is present else return pointer pointing to set.end()
//set.lower_bound(element) - iterator pointing to element greater than or equal to the given element
//set.upper_bound(element) - iterator pointing to element greater than the given element
// | ^
//__builtin_popcount(x)
using namespace std;
const ll MOD=1e9+7;
vll h,w;
ll bin(ll x){
return ((x*(x+1))/2)%MOD;
}
ll T(ll x,ll y){
return (bin(x)%MOD*bin(y)%MOD)%MOD;
}
int main()
{
int n,x;
cin>>n;
ll y;
for(int i=0;i<n;i++){
cin>>x;
y=x;
h.pb(x);
}
ll sum=0;
for(int i=0;i<n;i++){
cin>>x;
sum+=x;sum%=MOD;
w.pb(x);
}
ll res=T(1,sum);
ll sum=0;
for(int i=0;i<n;i++){
if(h[i]==2){
sum+=w[i];
}else{
res+=T(sum,2);res%=MOD;
res-=T(sum,1);res%=MOD;
sum=0;
}
}
res+=T(sum,2);res%=MOD;
res-=T(sum,1);res%=MOD;
cout<<res<<endl;
return 0;
}
Compilation message
fancyfence.cpp: In function 'int main()':
fancyfence.cpp:47:8: error: redeclaration of 'long long int sum'
47 | ll sum=0;
| ^~~
fancyfence.cpp:40:8: note: 'long long int sum' previously declared here
40 | ll sum=0;
| ^~~
