题解 | 元素方碑

zu = int(input())
while True:
    try:
        n = int(input())
        l = list(map(int,input().split()))
        s = 0
        for i in l:
            s += i
        s1 = 0
        s2 = 0
        if n % 2 == 0:
            for i in range(0,n-1,2):
                s2 += l[i]
            for i in range(1,n,2):
                s1 += l[i]
        else:
            for i in range(0,n,2):
                s2 += l[i]
            for i in range(1,n-1,2):
                s1 += l[i]
        p = s // n
        if s1 % p == 0 and s2 % p == 0:
            print('YES')
        else:
            print('NO')
    except:
        break