C++,codeforces,2050B,B. Transfusion

//B. Transfusion
#include <iostream>
#include <vector>
void solve(){
    int n;
    std::cin>>n;
    int countOfOdd = (n+1)/2;
    int countOfEven = n/2;
    long long sumOfOdd=0;
    long long sumOfEven=0;
    for(int i = 0;i<n;i+=2){
        int odd,even=0;
        std::cin>>odd;
        if(i+1<n){
            std::cin>>even;
        }
        sumOfOdd+=odd;
        sumOfEven+=even;
    }

    if(sumOfOdd%countOfOdd==0 && sumOfEven%countOfEven==0 && (sumOfOdd/countOfOdd)==(sumOfEven/countOfEven)){
        std::cout<<"YES"<<std::endl;
    }else{
        std::cout<<"NO"<<std::endl;
    }
}
int main(){
    int t;
    std::cin>>t;
    while(t--){
        solve();
    }
}