Good array (Editorial)

Solution

Notice that are no restrictions on distinct elements of the array thus we can consider two elements $a$ and $b$ for the array such that \gcd(a,b)=x and \text{lcm}(a,b)=y , Notice that a \cdot b =\gcd(a,b) \cdot \text{lcm}(a,b) , which forces \text{lcm}(a,b) to be divisible by \gcd(a,b) thus a solution exist if \text{lcm}(a,b) \bmod \gcd(a,b)=0 which means a solution exist if y \bmod x=0.

The minimal solution holds for the array [\underbrace{x,x,x,...,x}_{n-1 \text{ times}},y] , since it's always guaranteed that x \le y.

The only edge case is when n=1 then x=y must hold.

Complexity $\mathcal{O}(1)$.

for _ in range(int(input())):
    n,x,y=map(int,input().split())
    if(n==1):
        if(x==y):
            print(x)
        else:
            print(-1)
    else:
        if(y%x==0):
            print(*([x]*(n-1)+[y]))
        else:
            print(-1)