Project Name: ASPP+pelita
Language: Python
Statement Type: Constant Assignment

Source Code:
def initial_positions(walls):
    """Calculate initial positions.

    Given the list of walls, returns the free positions that are closest to the
    bottom left and top right corner. The algorithm starts searching from
    (1, height-2) and (width-2, 1) respectively and uses the Manhattan distance
    for judging what is closest. On equal distances, a smaller distance in the
    x value is preferred.
    """
    width = max(walls)[0] + 1
    height = max(walls)[1] + 1

    left_start = (1, height - 2)
    left = []
    right_start = (width - 2, 1)
    right = []

    dist = 0
    while len(left) < 2:
        # iterate through all possible x distances (inclusive)
        for x_dist in range(dist + 1):
            y_dist = dist - x_dist
            pos = (left_start[0] + x_dist, left_start[1] - y_dist)
            # if both coordinates are out of bounds, we stop
            if not (0 <= pos[0] < width) and not (0 <= pos[1] < height):
                raise ValueError("Not enough free initial positions.")
            # if one coordinate is out of bounds, we just continue
            if not (0 <= pos[0] < width) or not (0 <= pos[1] < height):
                continue
            # check if the new value is free
            if pos not in walls:
                left.append(pos)

            if len(left) == 2:
                break

        dist += 1

    dist = 0
    while len(right) < 2:
        # iterate through all possible x distances (inclusive)
        for x_dist in range(dist + 1):
            y_dist = dist - x_dist
            pos = (right_start[0] - x_dist, right_start[1] + y_dist)
            # if both coordinates are out of bounds, we stop
            if not (0 <= pos[0] < width) and not (0 <= pos[1] < height):
                raise ValueError("Not enough free initial positions.")
            # if one coordinate is out of bounds, we just continue
            if not (0 <= pos[0] < width) or not (0 <= pos[1] < height):
                continue
            # check if the new value is free
            if pos not in walls:
                right.append(pos)

            if len(right) == 2:
                break

        dist += 1

    # lower indices start further away
    left.reverse()
    right.reverse()
    return [left[0], right[0], left[1], right[1]]

initial_positions(walls=[(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 3), (2, 0), (2, 1), (2, 3), (3, 0), (3, 1), (3, 3), (4, 0), (4, 1), (4, 3), (5, 0), (5, 3), (6, 0), (6, 3), (7, 0), (7, 1), (7, 2), (7, 3)])

Selected Statement: dist = 0

Function Input:
walls: [(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 3), (2, 0), (2, 1), (2, 3), (3, 0), (3, 1), (3, 3), (4, 0), (4, 1), (4, 3), (5, 0), (5, 3), (6, 0), (6, 3), (7, 0), (7, 1), (7, 2), (7, 3)]

Variable Values Before Statement:
Constant: 0

Value After Statement Execution: 0

Variable States During Runtime (line, value):
walls: 1
[(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 3), (2, 0), (2, 1), (2, 3), (3, 0), (3, 1), (3, 3), (4, 0), (4, 1), (4, 3), (5, 0), (5, 3), (6, 0), (6, 3), (7, 0), (7, 1), (7, 2), (7, 3)]
width: 10
8
height: 11
4
left_start: 13
(1, 2)
left: 14
32
[(1, 2)]
32
[(1, 2), (1, 1)]
61
[(1, 1), (1, 2)]
right_start: 15
(6, 1)
right: 16
53
[(6, 1)]
53
[(6, 1), (6, 2)]
62
[(6, 2), (6, 1)]
dist: 18
0
37
1
37
2
39
0
58
1
58
2
x_dist: 21
0
y_dist: 22
0
22
1
43
0
43
1
pos: 23
(1, 2)
23
(1, 1)
44
(6, 1)
44
(6, 2)