68. 文本左右对齐(字符串)(Leetcode困难)

68. 文本左右对齐

class Solution {
public:
    vector<string> fullJustify(vector<string>& words, int maxWidth) {
        //最后一行左对齐,或者这一行只包含一个单词左对齐
        //包含多个单词 左右对齐
        //先统计能放多少个单词
        vector<string> res;
        for(int i = 0; i < words.size(); ++i){
            int j = i + 1;
            int len = words[i].size();
            while(j < words.size() && len + 1 + words[j].size() <= maxWidth) len += 1 + words[j++].size();

            string line = "";
            if(j == words.size() || j == i + 1) { //左对齐
                line += words[i];
                for(int k = i + 1; k < j; ++k) line += " " + words[k];
                while(line.size() < maxWidth) line += " ";
            }else{ //左右对齐
                //cnt个空隙, r个空格要插
                int cnt = j - i - 1, r = maxWidth - len + cnt;
                line += words[i];
                int k = 0;
                //放左边多的
                while(k < r % cnt) line += string(r / cnt + 1, ' ') + words[i + k + 1], ++k;
                while(k < cnt) line += string(r / cnt, ' ') + words[i + k + 1], ++k;
                //再放右边
            }
            res.push_back(line);
            i = j - 1;
        }
        return res;
    }

};