Study Plan For Algorithms - Part34

1. 二进制求和
给定两个二进制字符串 a 和 b ，以二进制字符串的形式返回它们的和。

class Solution:
    def addBinary(self, a: str, b: str) -> str:
        i = len(a) - 1
        j = len(b) - 1
        carry = 0
        result = []

        while i >= 0 or j >= 0 or carry:
            digit_a = int(a[i]) if i >= 0 else 0
            digit_b = int(b[j]) if j >= 0 else 0

            sum_digits = digit_a + digit_b + carry
            carry = sum_digits // 2
            result.append(str(sum_digits % 2))

            i -= 1
            j -= 1

        return ''.join(result[::-1])

2. 文本左右对齐
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。

class Solution {
    public List<String> fullJustify(String[] words, int maxWidth) {
        List<String> stringList = new ArrayList<>();
        List<Integer> index = new ArrayList<>();
        int width = 0;
        int length = 0;
        StringBuilder stringBuilder;
        for (int i = 0; i < words.length; ) {
            width += words[i].length();
            length = width - words[i].length();
            if (width < maxWidth - index.size() + 1) {
                index.add(i);
                i++;
            } else {
                int nullLen = (maxWidth - length);
                stringBuilder = new StringBuilder();
                int after = (index.size() - 1) == 0? 1 : index.size() - 1;
                int[] arrs = new int[after];
                for (int j = 0; nullLen > 0; ) {
                    arrs[j]++;
                    nullLen--;
                    j = (j + 1) % arrs.length;
                }
                for (int j = 0; j < index.size(); j++) {
                    if (j!= index.size() - 1 || j == 0) {
                        stringBuilder.append(words[index.get(j)]);
                        for (int k = 0; k < arrs[j]; k++) {
                            stringBuilder.append(" ");
                        }
                    } else {
                        stringBuilder.append(words[index.get(j)]);
                    }
                }
                stringList.add(stringBuilder.toString());
                width = 0;
                index = new ArrayList<>();
            }
        }
        length = 0;
        for (Integer i : index) {
            length += words[i].length();
        }
        stringBuilder = new StringBuilder();
        for (int i = 0; i < index.size(); i++) {
            if (i == index.size() - 1) {
                stringBuilder.append(words[index.get(i)]);
            } else {
                stringBuilder.append(words[index.get(i)]).append(" ");
                length++;
            }
        }
        for (int i = 0; i < maxWidth - length; i++) {
            stringBuilder.append(" ");
        }
        stringList.add(stringBuilder.toString());
        return stringList;
    }
}