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| # Slow. Should use something like this instead https://www.geeksforgeeks.org/largest-rectangle-under-histogram/ | |
| rows, cols = (8, 8) | |
| arr = [[0]*cols]*rows | |
| arr[0] = [0, 0, 0, 0, 0, 0, 0, 0] | |
| arr[1] = [0, 1, 0, 1, 1, 0, 1, 0] | |
| arr[2] = [0, 1, 0, 1, 1, 0, 1, 0] | |
| arr[3] = [0, 1, 0, 1, 1, 0, 1, 0] | |
| arr[4] = [0, 1, 0, 1, 1, 0, 1, 0] | |
| arr[5] = [0, 1, 0, 0, 0, 0, 1, 0] | |
| arr[6] = [0, 1, 1, 1, 1, 1, 1, 0] | |
| arr[7] = [0, 0, 0, 0, 0, 0, 0, 0] | |
| print(arr) | |
| def hist_largest_rect(hist): | |
| print("hist_largest_rect", hist) | |
| largest_area = 0 | |
| largest_x = 0 | |
| largest_y = 0 | |
| largest_width = 0 | |
| largest_height = 0 | |
| for x in range(0, len(hist)): | |
| # print("check {} ---".format(x)) | |
| if hist[x] == 0: | |
| continue | |
| # Find out how long we can go | |
| endX = x | |
| for i in range(x, len(hist)): | |
| if i + 1 == 8: | |
| endX = i + 1 | |
| break | |
| if hist[i+1] == 0: | |
| endX = i + 1 | |
| break | |
| # print("hist length is", (endX - x)) | |
| rect_width = endX - x | |
| # Find the smallest value in this range | |
| rect_height = 999 | |
| for i in range(x, endX): | |
| if hist[i] < rect_height: | |
| rect_height = hist[i] | |
| # print("height:", rect_height) | |
| # | |
| print("Rect (height check): {} x {} = {}".format(rect_width, rect_height, rect_width * rect_height)) | |
| area = rect_width * rect_height | |
| if area > largest_area: | |
| largest_area = area | |
| largest_x = x | |
| largest_width = rect_width | |
| largest_height = rect_height | |
| # Fit largest rectangle that is hist[x] high from x up to endX (if possible) | |
| endX2 = x | |
| for i in range(x, endX): | |
| if i + 1 == 8: | |
| endX2 = i + 1 | |
| break | |
| if hist[i+1] < hist[x]: | |
| endX2 = i + 1 | |
| break | |
| print("endX 2 is {}".format(endX2)) | |
| rect_width = endX2 - x | |
| rect_height = hist[x] | |
| print("Rect (length check): {} x {} = {}".format(rect_width, rect_height, rect_width * rect_height)) | |
| area = rect_width * rect_height | |
| if area > largest_area: | |
| largest_area = area | |
| largest_x = x | |
| largest_y = hist[x] | |
| largest_width = rect_width | |
| largest_height = rect_height | |
| print("Largest: {} x {} at x = {}, y = {}".format(largest_width, largest_height, largest_x, largest_y)) | |
| print("returning", largest_area) | |
| return (largest_x, largest_y, largest_width, largest_height, largest_area) | |
| # hist_largest_rect([0, 1, 4, 0, 3, 4, 5, 2]) | |
| # | |
| # exit(1) | |
| largest_rect=(0,0,0,0,0) | |
| largest_rect_row = 0 | |
| hist = [0, 0, 0, 0, 0, 0, 0, 0] | |
| for row in range(0, 8): | |
| print("Calculate row", row) | |
| for x in range(0, 8): | |
| if arr[row][x] == 0: | |
| hist[x] = 0 | |
| else: | |
| hist[x] = hist[x] + 1 | |
| rect = hist_largest_rect(hist) | |
| if rect[4] > largest_rect[4]: | |
| largest_rect = rect | |
| largest_rect_row = row | |
| print("Largest: ", largest_rect) | |
| print("Largest at row", largest_rect_row) | |
| # print(hist) |
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