hard_puzzles.py

def hard1():
    puzzle = [[7, 0, 0, 0, 0, 5, 0, 0, 0],
              [0, 0, 0, 1, 0, 4, 6, 5, 0],
              [0, 0, 0, 0, 6, 0, 3, 0, 1],
              [3, 0, 6, 4, 0, 0, 0, 0, 0],
              [0, 0, 4, 8, 0, 0, 1, 0, 9],
              [9, 0, 0, 0, 7, 0, 4, 6, 0],
              [0, 0, 0, 0, 0, 3, 0, 0, 2],
              [5, 0, 0, 0, 0, 0, 9, 0, 0],
              [1, 0, 8, 0, 4, 0, 5, 0, 0]]
    return puzzle

def hard2():
    puzzle = [[0, 0, 9, 0, 0, 0, 3, 0, 0],
              [0, 0, 1, 0, 0, 4, 9, 6, 0],
              [0, 6, 0, 0, 8, 0, 0, 0, 4],
              [8, 0, 6, 4, 5, 3, 0, 9, 0],
              [0, 0, 0, 0, 0, 0, 0, 8, 0],
              [5, 0, 0, 0, 6, 0, 0, 3, 0],
              [6, 0, 2, 0, 4, 0, 0, 0, 0],
              [0, 1, 3, 5, 0, 0, 0, 0, 0],
              [0, 0, 0, 0, 2, 0, 1, 0, 0]]
    return puzzle

def hard3():
    puzzle = [[8, 0, 0, 0, 0, 0, 0, 0, 3],
              [0, 0, 3, 0, 0, 4, 7, 0, 0],
              [0, 0, 2, 0, 0, 0, 0, 0, 0],
              [0, 0, 1, 5, 8, 0, 9, 7, 0],
              [3, 0, 0, 0, 0, 0, 8, 5, 1],
              [0, 0, 5, 0, 0, 0, 0, 0, 4],
              [9, 0, 0, 0, 0, 7, 0, 0, 0],
              [0, 0, 0, 4, 0, 6, 2, 0, 0],
              [0, 0, 0, 8, 0, 0, 6, 4, 9]]
    return puzzle

def hard4():
    puzzle = [[5, 7, 9, 0, 0, 2, 8, 0, 0],
              [2, 0, 0, 8, 0, 0, 7, 0, 9],
              [0, 0, 8, 0, 0, 0, 2, 6, 0],
              [0, 0, 7, 0, 0, 0, 0, 0, 6],
              [0, 5, 4, 0, 9, 6, 0, 0, 0],
              [0, 1, 0, 0, 7, 0, 0, 0, 0],
              [0, 6, 0, 7, 2, 0, 4, 0, 0],
              [0, 0, 3, 6, 0, 0, 0, 0, 7],
              [0, 2, 0, 4, 0, 0, 6, 0, 0]]
    return puzzle