import lib

EXAMPLE = """
Sabqponm
abcryxxl
accszExk
acctuvwj
abdefghi
"""

def neighbors_4(row, col, rows, cols):
    n = []
    for r, c in [(1, 0), (-1, 0), (0, 1), (0, -1)]:
        new_row, new_col = row + r, col + c
        if new_row >= 0 and new_row < rows and new_col >= 0 and new_col < cols:
            n.append((new_row, new_col))
    return n

def solve(lines: list[str]):
    start = (0, 0)
    end = (0, 0)
    rows = len(lines)
    cols = len(lines[0])
    heights = []
    dists = []
    for (row, line) in enumerate(lines):
        heights.append([])
        dists.append([])
        for (col, c) in enumerate(line):
            if c == 'S':
                start = (row, col)
                heights[row].append(0)
                dists[row].append(0)
            elif c == 'E':
                end = (row, col)
                heights[row].append(26)
                dists[row].append(2**16)
            else:
                heights[row].append(ord(lines[row][col]) - ord('a'))
                dists[row].append(2**16)

    active_fields = [start]
    while active_fields:
        row, col = active_fields.pop()
        current_dist = dists[row][col]
        current_height = heights[row][col]
        for row, col in neighbors_4(row, col, rows, cols):
            pot_height = heights[row][col]
            if current_height < pot_height - 1:
                continue
            if current_dist + 1 < dists[row][col]:
                dists[row][col] = current_dist + 1
                active_fields.append((row, col))

    # for row in dists:
    #     print(row)

    # 34:00
    return dists[end[0]][end[1]]

def solve2(lines: list[str]):
    starts = []
    all_dists =[]
    for (row, line) in enumerate(lines):
        for (col, c) in enumerate(line):
            if c == 'S' or c == 'a':
                starts.append((row, col))

    for start in starts:
        end = (0, 0)
        rows = len(lines)
        cols = len(lines[0])
        heights = []
        dists = []
        for (row, line) in enumerate(lines):
            heights.append([])
            dists.append([])
            for (col, c) in enumerate(line):
                if row == start[0] and col == start[1]:
                    heights[row].append(0)
                    dists[row].append(0)
                elif c == 'E':
                    end = (row, col)
                    heights[row].append(26)
                    dists[row].append(2**16)
                else:
                    heights[row].append(ord(lines[row][col]) - ord('a'))
                    dists[row].append(2**16)

        active_fields = [start]
        while active_fields:
            row, col = active_fields.pop()
            current_dist = dists[row][col]
            current_height = heights[row][col]
            for row, col in neighbors_4(row, col, rows, cols):
                pot_height = heights[row][col]
                if current_height < pot_height - 1:
                    continue
                if current_dist + 1 < dists[row][col]:
                    dists[row][col] = current_dist + 1
                    active_fields.append((row, col))
        all_dists.append(dists[end[0]][end[1]])
    # 39:45
    return min(all_dists)

def main():
    lines = lib.str_to_lines_no_empty(EXAMPLE)
    print("Example  1:", solve(lines))

    lines = lib.str_to_lines_no_empty(open("i12.txt").read())
    print("Solution 1:", solve(lines))

    lines = lib.str_to_lines_no_empty(EXAMPLE)
    print("Example  2:", solve2(lines))

    lines = lib.str_to_lines_no_empty(open("i12.txt").read())
    print("Solution 2:", solve2(lines))

if __name__ == "__main__":
    main()