练习-二维数组旋转

Posted 2020-09-04

#slist = [[i for i in range(4)] for l in range(8)]

# slist = [
#     [4, 5, 2, 7],
#     [8, 7, 4, 2],
#     [1, 9, 7, 3],
#     [0, 4, 5, 6],
# ]  # 4*4

slist = [
    [4, 5, 2, 7],
    [8, 7, 4, 2],
    [1, 9, 7, 3],
    [0, 4, 5, 6],
    [1, 9, 7, 3],
]  # 4*5

# slist = [
#     [1, 0, 1, 8, 4],
#     [9, 4, 9, 7, 5],
#     [7, 5, 7, 4, 2],
#     [3, 6, 3, 2, 7]
# ]  # 5*4

# slist = [
#     [1, 0, 1, 8, 4],
#     [9, 4, 9, 7, 5],
#     [7, 5, 7, 4, 2],
#     [3, 6, 3, 2, 7],
#     [7, 5, 7, 4, 2],
# ]  # 5*5


# 旋转90°
def rotate_90(lists):
    row = len(lists)  # 行
    column = len(lists[0])  # 列
    if row == column:  # 行列相等
        olist = [[i for i in range(column)] for l in range(row)]  # 生成新列表
    else:  # 行列不等
        olist = [[i for i in range(row)] for l in range(column)]  # 生成新列表
    for i in range(row):
        for l in range(column):
            #print(‘%d%d换%d%d‘ % (i, l, l, abs(i - row + 1)))
            olist[l][abs(i - row + 1)] = lists[i][l]
    return olist


olist = rotate_90(slist)
print(‘正常数组:%r\n转90°后数组:%r‘ % (slist, olist))

# 分解步骤如下,数字等于二维数组索引
#    原数组              4行4列              新数组
# [4, 5, 2, 7]00到03,01到13,02到23,03到33[0, 1, 8, 4]
# [8, 7, 4, 2]10到02,11到12,12到22,13到32[4, 9, 7, 5]
# [1, 9, 7, 3]20到01,21到11,22到21,23到31[5, 7, 4, 2]
# [0, 4, 5, 6]30到00,31到10,32到20,33到30[6, 3, 2, 7]

#    原数组              5行4列              新数组
# [4, 5, 2, 7]00到04,01到14,02到24,03到34[1, 0, 1, 8, 4]
# [8, 7, 4, 2]10到03,11到13,12到23,13到33[9, 4, 9, 7, 5]
# [1, 9, 7, 3]20到02,21到12,22到22,23到32[7, 5, 7, 4, 2]
# [0, 4, 5, 6]30到01,31到11,32到21,33到31[3, 6, 3, 2, 7]
# [1, 9, 7, 3]40到00,41到10,42到20,43到30

#      原数组                4行5列                   新数组
# [1, 0, 1, 8, 4]00到03,01到13,02到23,03到33,04到43[3, 7, 9, 1]
# [9, 4, 9, 7, 5]10到02,11到12,12到22,13到32,14到42[6, 5, 4, 0]
# [7, 5, 7, 4, 2]20到01,21到11,22到21,23到31,24到41[3, 7, 9, 1]
# [3, 6, 3, 2, 7]30到00,31到10,32到20,33到30,34到40[2, 4, 7, 8]
#                                                 [7, 2, 5, 4]


# 旋转180度
def rotate_180(lists):
    row = len(lists)  # 行
    column = len(lists[0])  # 列
    olist = [[i for i in range(column)] for l in range(row)]  # 生成新列表
    remainder = row % 2
    for i in range(row // 2 + remainder):
        for l in range(column):
            # 先判断奇偶行--是奇数行,再判断是否在操作中间行--列表是奇数行,当前也在中间行,超过中间列就停止
            # 因为偶数中间行是上下行对角互换,所以要按列依次互换
            # 奇数中间行是在中间行左右互换,所以超过中间列就不再继续互换
            if remainder == 1 and i == (row - 1) // 2 and l > (column - 1) // 2:
                break
            # 原位置,互换位置依次取值
            olist[abs(i - row + 1)][abs(l - column + 1)] = lists[i][l]
            olist[i][l] = lists[abs(i - row + 1)][abs(l - column + 1)]
    return olist

olist = rotate_180(slist)
print(‘正常数组:%r\n转180°后数组:%r‘ % (slist, olist))

# 分解步骤如下,数字等于二维数组索引
#    原数组              偶数行              新数组
# [4, 5, 2, 7]00换33,01换32,02换31,03换30[6, 5, 4, 0]
# [8, 7, 4, 2]10换23,11换22,12换21,13换20[3, 7, 9, 1]
# [1, 9, 7, 3]                          [2, 4, 7, 8]
# [0, 4, 5, 6]                          [7, 2, 5, 4]

#    原数组              奇数行              新数组
# [4, 5, 2, 7]00换43,01换42,02换41,03换40[3, 7, 9, 1]
# [8, 7, 4, 2]10换33,11换32,12换31,13换30[6, 5, 4, 0]
# [1, 9, 7, 3]20换23,21换22              [3, 7, 9, 1]
# [0, 4, 5, 6]                           [2, 4, 7, 8]
# [1, 9, 7, 3]                           [7, 2, 5, 4]


# 旋转270度
def rotate_270(lists):
    row = len(lists)
    column = len(lists[0])
    if row == column:  # 行列相等
        olist = [[i for i in range(column)] for l in range(row)]  # 生成新列表
    else:
        olist = [[i for i in range(row)] for l in range(column)]  # 生成新列表
    for i in range(row):
        for l in range(column):
            # print(‘%d%d换%d%d‘ % (i, l, abs(l - column + 1), i))
            olist[abs(l - column + 1)][i] = lists[i][l]
    return olist

olist = rotate_270(slist)
print(‘正常数组:%r\n转270°后数组:%r‘ % (slist, olist))

# 分解步骤如下,数字等于二维数组索引
#    原数组              4行4列              新数组
# [4, 5, 2, 7]00到30,01到20,02到10,03到00[7, 2, 3, 6]
# [8, 7, 4, 2]10到31,11到21,12到11,13到01[2 ,4, 7, 5]
# [1, 9, 7, 3]20到32,21到22,22到12,23到02[5, 7, 9, 4]
# [0, 4, 5, 6]30到33,31到23,32到13,33到03[4, 8, 1, 0]


#    原数组              5行4列              新数组
# [4, 5, 2, 7]00到30,01到20,02到10,03到00[7, 2, 3, 6, 3]
# [8, 7, 4, 2]10到31,11到21,12到11,13到01[2, 4, 7, 5, 7]
# [1, 9, 7, 3]20到32,21到22,22到12,23到02[5, 7, 9, 4, 9]
# [0, 4, 5, 6]30到33,31到23,32到13,33到03[4, 8, 1, 0, 1]
# [1, 9, 7, 3]40到34,41到24,42到14,43到04

#      原数组                4行5列                   新数组
# [1, 0, 1, 8, 4]00到40,01到30,02到20,03到10,04到00[4, 5, 2, 7]
# [9, 4, 9, 7, 5]10到41,11到31,12到21,13到11,14到01[8, 7, 4, 2]
# [7, 5, 7, 4, 2]20到42,21到32,22到22,23到12,24到02[1, 9, 7, 3]
# [3, 6, 3, 2, 7]30到43,31到33,32到23,33到13,34到03[0, 4, 5, 6]
#                                                 [1, 9, 7, 3]


#正方形对角互换(左上到右下连线分成右上和左下两个区域互换)
print(‘对角交换前数组:%r‘ % slist)
for i in range(len(slist)):
    for l in range(len(slist[0])):
        if i < l:
            tint = slist[i][l]
            slist[i][l] = slist[l][i]
            slist[l][i] = tint
print(‘对角交换后数组:%r‘ % slist)

# 分解步骤如下,数字等于二维数组索引
#    原数组                         新数组
# [4, 5, 2, 7]01换10,02换20,03换30[4, 8, 1, 0]
# [8, 7, 4, 2]12换21,13换31       [5, 7, 9, 4]
# [1, 9, 7, 3]23换32              [2, 4, 7, 5]
# [0, 4, 5, 6]                    [7, 2, 3, 6]