1955B - Progressive Square - CodeForces Solution

from collections import Counter

for t in range(int(input())):
    n, c, d = map(int, input().split())
    b = Counter(map(int, input().split()))
    r = True
    a1 = min(b)
    for i in range(n):
        for j in range(n):
            x = a1 + i * c + j * d
            if b[x] == 0:
                r = False
                break
            b[x] -= 1
    if r:
        print("YES")
    else:
        print("NO")