多伦多大学CSC108Assignment2课业解析题意： 按照功能描述完成8个函数，对矩阵进行一定操作 解析： 3*3矩阵定义如下： THREE_BY_THREE = [[1, 2, 1], [4, 6, 5], [7, 8, 9]] 第一个函数compare_elevations_within_row(elevation_map: List[List[int]], map_row: int,level: int) -> List[int],接收三个参数分别是矩阵、要比较的行、要比较的值，compare_elevations_within_row(THREE_BY_THREE, 1, 5)即找到上述矩阵第一行，比5小的数、等于5的数和大于5的数，并以列表形式返回，即[1, 1, 1]；第二个函数把起点到终点元素之间（含起点和终点）所有元素的值加上delta，若结果大于1保留修改否则取消；第三个函数和第四个函数都需要遍历所有元素，前者计算平均值，后者返回最大值的行列坐标。 涉及知识点： python 列表，函数 更多可加微信讨论 微信号ITCSdaixie pdf”””Assignment 2 functions.””” from typing import List THREE_BY_THREE = [[1, 2, 1], [4, 6, 5], [7, 8, 9]] FOUR_BY_FOUR = [[1, 2, 6, 5], [4, 5, 3, 2], [7, 9, 8, 1], [1, 2, 1, 4]] UNIQUE_3X3 = [[1, 2, 3], [9, 8, 7], [4, 5, 6]] UNIQUE_4X4 = [[10, 2, 3, 30], [9, 8, 7, 11], [4, 5, 6, 12], [13, 14, 15, 16]] def compare_elevations_within_row(elevation_map: List[List[int]], map_row: int, level: int) -> List[int]: “”” Return a new list containing the three counts: the number of elevations from row number map_row of elevation map elevation_map that are less than, equal to, and greater than elevation level. Precondition: elevation_map is a valid elevation map. 0 <= map_row < len(elevation_map). >>> compare_elevations_within_row(THREE_BY_THREE, 1, 5) [1, 1, 1] >>> compare_elevations_within_row(FOUR_BY_FOUR, 1, 2) [0, 1, 3] “”” pass # remove this line when you implement this function def update_elevation(elevation_map: List[List[int]], start: List[int], stop: List[int], delta: int) -> None: “””Modify elevation map elevation_map so that the elevation of each cell between cells start and stop, inclusive, changes by amount delta.Precondition: elevation_map is a valid elevation map. start and stop are valid cells in elevation_map. start and stop are in the same row or column or both. If start and stop are in the same row, start’s column <= stop's column. If start and stop are in the same column, start's row <= stop's row. elevation_map[i, j] + delta >= 1 for each cell [i, j] that will change.>>> THREE_BY_THREE_COPY = [[1, 2, 1], … [4, 6, 5], … [7, 8, 9]] >>> update_elevation(THREE_BY_THREE_COPY, [1, 0], [1, 1], -2) >>> THREE_BY_THREE_COPY [[1, 2, 1], [2, 4, 5], [7, 8, 9]]>>> FOUR_BY_FOUR_COPY = [[1, 2, 6, 5], … [4, 5, 3, 2], … [7, 9, 8, 1], … [1, 2, 1, 4]]>>> update_elevation(FOUR_BY_FOUR_COPY, [1, 2], [3, 2], 1)>>> FOUR_BY_FOUR_COPY [[1, 2, 6, 5], [4, 5, 4, 2], [7, 9, 9, 1], [1, 2, 2, 4]] “”” pass # remove this line when you implement this function def get_average_elevation(elevation_map: List[List[int]]) -> float: “””Return the average elevation across all cells in the elevation map elevation_map. Precondition: elevation_map is a valid elevation map.>>> get_average_elevation(UNIQUE_3X3) 5.0>>> get_average_elevation(FOUR_BY_FOUR) 3.8125 “”” pass # remove this line when you implement this function def find_peak(elevation_map: List[List[int]]) -> List[int]: “””Return the cell that is the highest point in the elevation map elevation_map. Precondition: elevation_map is a valid elevation map. Every elevation value in elevation_map is unique. >>> find_peak(UNIQUE_3X3) [1, 0] >>> find_peak(UNIQUE_4X4) [0, 3] “”” pass # remove this line when you implement this function def is_sink(elevation_map: List[List[int]], cell: List[int]) -> bool:”””Return True if and only if cell exists in the elevation map elevation_map and cell is a sink. Precondition: elevation_map is a valid elevation map. cell is a 2-element list. >>> is_sink(THREE_BY_THREE, [0, 5]) False >>> is_sink(THREE_BY_THREE, [0, 2]) True >>> is_sink(THREE_BY_THREE, [1, 1]) False >>> is_sink(FOUR_BY_FOUR, [2, 3]) True >>> is_sink(FOUR_BY_FOUR, [3, 2]) True >>> is_sink(FOUR_BY_FOUR, [1, 3]) False “”” pass # remove this line when you implement this function def find_local_sink(elevation_map: List[List[int]], cell: List[int]) -> List[int]: “””Return the local sink of cell cell in elevation map elevation_map. Precondition: elevation_map is a valid elevation map. elevation_map contains no duplicate elevation values. cell is a valid cell in elevation_map. >>> find_local_sink(UNIQUE_3X3, [1, 1]) [0, 0] >>> find_local_sink(UNIQUE_3X3, [2, 0]) [2, 0] >>> find_local_sink(UNIQUE_4X4, [1, 3]) [0, 2] >>> find_local_sink(UNIQUE_4X4, [2, 2]) [2, 1] “”” pass # remove this line when you implement this function def can_hike_to(elevation_map: List[List[int]], start: List[int], dest: List[int], supplies: int) -> bool: “””Return True if and only if a hiker can go from start to dest in elevation_map without running out of supplies. Precondition: elevation_map is a valid elevation map. start and dest are valid cells in elevation_map. dest is North-West of start. supplies >= 0 >>> map = [[1, 6, 5, 6], … [2, 5, 6, 8], … [7, 2, 8, 1], … [4, 4, 7, 3]]>>> can_hike_to(map, [3, 3], [2, 2], 10)True>>> can_hike_to(map, [3, 3], [2, 2], 8)False>>> can_hike_to(map, [3, 3], [3, 0], 7)True >>> can_hike_to(map, [3, 3], [3, 0], 6)False>>> can_hike_to(map, [3, 3], [0, 0], 18)True>>> can_hike_to(map, [3, 3], [0, 0], 17)False “”” pass # remove this line when you implement this functiondef get_lower_resolution(elevation_map: List[List[int]]) -> List[List[int]]: “””Return a new elevation map, which is constructed from the values of elevation_map by decreasing the number of elevation points within it. Precondition:elevation_map is a valid elevation map.>>> get_lower_resolution( … [[1, 6, 5, 6], … [2, 5, 6, 8], … [7, 2, 8, 1], … [4, 4, 7, 3]]) [[3, 6], [4, 4]]>>> get_lower_resolution( … [[7, 9, 1], … [4, 2, 1], … [3, 2, 3]]) [[5, 1], [2, 3]]””” pass # remove this line when you implement this function
