Envío 880

Código

def sol(arr , N):

    frontier = []
    result = []

    for idx in range(N-1, -1, -1):
        
        while(len(frontier) > 0 and arr[idx] >= frontier[0]):
            _ = frontier.pop(0)

        if len(frontier) == 0:
            cover = -1
        else:
            cover = frontier[0]

        frontier.append(arr[idx])

        result.append(cover)

    return result[::-1]
   
num_cases = int(input())

for i in range(num_cases):

    N = int(input())
    arr = [int(x) for x in input().split()]
    result =  sol(arr, N)
    str_result = ' '.join([str(r) for r in result])
    print(f"Case #{i+1}: {str_result}")