TextJustification.java

package hard;
import java.util.*;
/**
 * Created by fishercoder1534 on 10/9/16.
 */
public class TextJustification {

    public static List<String> fullJustify(String[] words, int L) {
        ArrayList<String> result = new ArrayList();
        if(words == null || words.length == 0)
            return result;
        int count = 0;
        int last = 0;
        for(int i = 0; i < words.length; i++){
            if(count + words[i].length() + (i-last) > L){
                int spaceNum = 0 ;
                int extraNum = 0;
                if(i - last - 1 > 0){
                    spaceNum = (L - count)/(i - last - 1);
                    extraNum = (L - count)%(i - last - 1);
                }
                StringBuilder sb = new StringBuilder();
                for(int j = last; j < i; j++){
                    sb.append(words[j]);
                    if(j < i-1){
                        for(int k = 0; k < spaceNum; k++){
                            sb.append(" ");
                        }
                        if(extraNum > 0){
                            sb.append(" ");
                        }
                        extraNum--;
                    }
                }
                for(int j = sb.length(); j < L; j++){
                    sb.append(" ");
                }
                result.add(sb.toString());
                count = 0;
                last = i;
            }
            count += words[i].length();
        }
        StringBuilder sb = new StringBuilder();
        for(int i = last; i < words.length; i++){
            sb.append(words[i]);
            if(sb.length() < L){
                sb.append(" ");
            }
        }
        for(int i = sb.length(); i < L; i++){
            sb.append(" ");
        }
        result.add(sb.toString());
        return result;
    }

    public static void main(String...args){
//        String[] words = new String[]{"This", "is", "an", "example", "of", "text", "justification."};
        String[] words = new String[]{"This", "is", "a", "good", "test!", "\n", "What", "do", "you", "\n", "think?", "\n", "I"
                , "think", "so", "too!"};
        int L = 16;
        List<String> result = fullJustify(words, L);
        for(String str : result) {
            System.out.println(str);
        }
    }
}