[LeetCode] Text Justification

Text Justification

Given an array of words and a length L, format the text such that each line has exactly L characters and is fully (left and right) justified.

You should pack your words in a greedy approach; that is, pack as many words as you can in each line. Pad extra spaces ' ' when necessary so that each line has exactlyL characters.

Extra spaces between words should be distributed as evenly as possible. If the number of spaces on a line do not divide evenly between words, the empty slots on the left will be assigned more spaces than the slots on the right.

For the last line of text, it should be left justified and no extra space is inserted between words.

For example,
words: ["This", "is", "an", "example", "of", "text", "justification."]
L: 16.

Return the formatted lines as:

[
   "This    is    an",
   "example  of text",
   "justification.  "
]

Note: Each word is guaranteed not to exceed L in length.

click to show corner cases.

Corner Cases:

• A line other than the last line might contain only one word. What should you do in this case?
  In this case, that line should be left-justified.

解題思路：

題意爲將句子的詞按兩端對齊。

題目本身不難，就是分情況討論即可。

class Solution {
public:
    vector<string> fullJustify(vector<string>& words, int maxWidth) {
        vector<string> result;
        
        int len = words.size();
        int i = 0;
        while(i < len){
            int lineLen = words[i].length();
            int j = i + 1;
            while(j<len && lineLen + 1 + words[j].length() <= maxWidth){
                lineLen = lineLen + 1 + words[j].length();
                j++;
            }
            
            string line = words[i];
            
            if(j == len){   //表示爲最後一行
                for(int m = i + 1; m<j; m++){
                    line = line + " " + words[m];
                }
                while(line.length() < maxWidth){
                    line = line + " ";
                }
            }else{          //表示中間行
                int leftSpace = maxWidth - lineLen; //中間還需要插入的空格數
                int spaceNumber = j - i - 1;        //詞數減一，表示中間的空白數
                if(spaceNumber == 0){              //只有一個詞
                    while(line.length() < maxWidth){
                        line = line + " ";
                    }
                }else{
                    int addedSpaceNum = leftSpace / spaceNumber;
                    int extra = leftSpace % spaceNumber;
                    for(int m = i + 1; m < j; m++){
                        line = line + " ";
                        for(int n = 0; n<addedSpaceNum; n++){
                            line = line + " ";
                        }
                        if(extra>0){
                            line = line + " ";
                            extra--;
                        }
                        line = line + words[m];
                    }
                }
            }
            result.push_back(line);
            i = j;
        }
        
        return result;
    }
};