chart of zeros and ones: 1 is land and 0 is water. An island is a group of land cells joined through their sides (horizontally or vertically; touching diagonally does not count). Everything outside the map is water.
Two islands have the same shape if one can be moved onto the other by sliding it, without rotating or mirroring.
Return how many different shapes appear among all the islands on the map.chart=[[1, 1, 0, 1, 1], [0, 0, 0, 0, 0], [1, 0, 0, 1, 1], [1, 0, 0, 0, 0]] → 2
The two horizontal two-cell strips share one shape, the vertical strip at the bottom left has another. Two shapes in total.
chart=[[1, 0], [1, 1], [0, 0], [0, 1], [1, 1]] → 2
Both islands are three-cell corners, but the second mirrors the first. Reflections and rotations are not allowed, so the shapes differ.
chart=[[0, 0], [0, 0]] → 0
chart.length, chart[i].length ≤ 50chart[i][j] is 0 or 1chart=[[1, 1, 0, 1, 1], [0, 0, 0, 0, 0], [1, 0, 0, 1, 1], [1, 0, 0, 0, 0]]
2
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