小编典典

将文本分为3个均匀大小的组的算法

algorithm

我想创建一种算法,将文本分为3个均等大小的组(基于文本长度)。由于这将用于换行符,因此需要保持文本的顺序。

例如,此字符串:

Just testing to see how this works.

将排序为:

Just testing   // 12 characters
to see how     // 10 characters
this works.    // 11 characters

有任何想法吗?


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2020-07-28

共1个答案

小编典典

同样来自Wikipedia上有关自动换行的文章的“最小衣衫program”动态程序可以适应您的需求。设置LineWidth = len(text)/n - 1并忽略有关超过行宽的无限惩罚的注释;与一起使用c(i, j)as 的定义P = 2


Code. I took the liberty of modifying the DP always to return exactly n lines, at the cost of increasing the running time from O(#words ** 2) to O(#words ** 2 * n).

def minragged(text, n=3):
    """
    >>> minragged('Just testing to see how this works.')
    ['Just testing', 'to see how', 'this works.']
    >>> minragged('Just testing to see how this works.', 10)
    ['', '', 'Just', 'testing', 'to', 'see', 'how', 'this', 'works.', '']
    """
    words = text.split()
    cumwordwidth = [0]
    # cumwordwidth[-1] is the last element
    for word in words:
        cumwordwidth.append(cumwordwidth[-1] + len(word))
    totalwidth = cumwordwidth[-1] + len(words) - 1  # len(words) - 1 spaces
    linewidth = float(totalwidth - (n - 1)) / float(n)  # n - 1 line breaks
    def cost(i, j):
        """
        cost of a line words[i], ..., words[j - 1] (words[i:j])
        """
        actuallinewidth = max(j - i - 1, 0) + (cumwordwidth[j] - cumwordwidth[i])
        return (linewidth - float(actuallinewidth)) ** 2
    # best[l][k][0] is the min total cost for words 0, ..., k - 1 on l lines
    # best[l][k][1] is a minimizing index for the start of the last line
    best = [[(0.0, None)] + [(float('inf'), None)] * len(words)]
    # xrange(upper) is the interval 0, 1, ..., upper - 1
    for l in xrange(1, n + 1):
        best.append([])
        for j in xrange(len(words) + 1):
            best[l].append(min((best[l - 1][k][0] + cost(k, j), k) for k in xrange(j + 1)))
    lines = []
    b = len(words)
    # xrange(upper, 0, -1) is the interval upper, upper - 1, ..., 1
    for l in xrange(n, 0, -1):
        a = best[l][b][1]
        lines.append(' '.join(words[a:b]))
        b = a
    lines.reverse()
    return lines

if __name__ == '__main__':
    import doctest
    doctest.testmod()
2020-07-28