leetcode68文本左右对齐

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给定一个单词数组 words 和一个长度 maxWidth ，重新排版单词，使其成为每行恰好有 maxWidth 个字符，且左右两端对齐的文本。

你应该使用 “贪心算法” 来放置给定的单词；也就是说，尽可能多地往每行中放置单词。必要时可用空格 ‘ ‘ 填充，使得每行恰好有 maxWidth 个字符。

要求尽可能均匀分配单词间的空格数量。如果某一行单词间的空格不能均匀分配，则左侧放置的空格数要多于右侧的空格数。

文本的最后一行应为左对齐，且单词之间不插入额外的空格。

注意:

• 单词是指由非空格字符组成的字符序列。
• 每个单词的长度大于 0，小于等于 maxWidth。
• 输入单词数组 words 至少包含一个单词。

示例 1:

输入: words = ["This", "is", "an", "example", "of", "text", "justification."], maxWidth = 16 输出: [ "This is an", "example of text", "justification. " ] 

示例 2:

输入:words = ["What","must","be","acknowledgment","shall","be"], maxWidth = 16 输出: [ "What must be", "acknowledgment ", "shall be " ] 解释: 注意最后一行的格式应为 "shall be " 而不是 "shall be", 因为最后一行应为左对齐，而不是左右两端对齐。 第二行同样为左对齐，这是因为这行只包含一个单词。 

示例 3:

输入:words = ["Science","is","what","we","understand","well","enough","to","explain","to","a","computer.","Art","is","everything","else","we","do"]，maxWidth = 20 输出: [ "Science is what we", "understand well", "enough to explain to", "a computer. Art is", "everything else we", "do " ] 

提示:

• 1 <= words.length <= 300
• 1 <= words[i].length <= 20
• words[i] 由小写英文字母和符号组成
• 1 <= maxWidth <= 100
• words[i].length <= maxWidth

package leetcode; import java.util.ArrayList; import java.util.List; public class FullJustify_69 { public List<String> fullJustify(String[] words, int maxWidth) { int start = 0; int length = 0; List<String> res = new ArrayList<>(); for (int i = 0; i < words.length; i++) { length += words[i].length(); if (length + i - start > maxWidth) { String s = genStr(words, start, i - 1, length - words[i].length(), maxWidth); res.add(s); length = words[i].length(); start = i; } } StringBuilder stringBuilder = new StringBuilder(); for (int i = start; i < words.length; i++) { stringBuilder.append(words[i]); if (i != words.length - 1) { stringBuilder.append(" "); } } for (int i = stringBuilder.length(); i < maxWidth; i++) { stringBuilder.append(" "); } res.add(stringBuilder.toString()); return res; } public String genStr(String[] words, int start, int end, int length, int maxWidth) { StringBuilder stringBuilder = new StringBuilder(); if (start == end) { stringBuilder.append(words[start]); for (int i = stringBuilder.length(); i < maxWidth; i++) { stringBuilder.append(" "); } return stringBuilder.toString(); } int nums = end - start; int leftWidth = maxWidth - length; int eSpaces = leftWidth / nums; int lSpaces = leftWidth % nums; StringBuilder space = new StringBuilder(); for (int i = 0; i < eSpaces; i++) { space.append(" "); } String strS = space.toString(); String strB = strS + " "; for (int i = start; i <= end; i++) { stringBuilder.append(words[i]); if (i == end) { break; } if (i < start + lSpaces) { stringBuilder.append(strB); } else { stringBuilder.append(strS); } } return stringBuilder.toString(); } public static void main(String[] args) { FullJustify_69 fullJustify_69 = new FullJustify_69(); String[] words = {"This", "is", "an", "example", "of", "text", "justification."}; int maxWidth = 16; List<String> strings = fullJustify_69.fullJustify(words, maxWidth); strings.stream().forEach(s -> System.out.println(s)); } }