def mana(s):
    p = [-1 for _ in range(len(s))]
    r = -1
    c = -1
    n = len(s)
    for i in range(n):
        if r >= i:
            p[i] = min(r-i, p[2*c - i])
        else:
            p[i] = 0
    
        while i + p[i] + 1 < n and i - p[i] - 1 >= 0:
            if s[i + p[i] + 1] == s[i - p[i] - 1]:
                p[i] += 1
            else:
                break
        
        if i + p[i] > r:
            r = i + p[i]
            c = i
    return p
        

T = int(input())
for i in range(T):
    ans = []
    n = int(input())
    p = list(map(int, input().split()))
    for j in range(2):
        for k in range(2):
            arr = [j, k]
            for l in range(2, n):
                arr.append(arr[l-2] ^ (p[l-1]==0))
            if mana(arr) == p:
                ans.append(''.join(map(str, arr)))
    print(len(ans))
    for j in range(len(ans)):
        print(ans[j])