#leetcode#Text Justification

L家高频题....

毫无头绪， 学习了code ganker大神的解法，做了适当注释

package TextJustification;import java.util.*;public class Solution {public ArrayList<String> fullJustify(String[] words, int L) {ArrayList<String> res = new ArrayList<String>();if (words == null || words.length == 0)return res;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); // (L - count) is the number of spaces to be inserted. (i - 1) is the index of last string in the current row, (i - 1 - last) is how many intervals to put space, so (L - count) / (i - last - 1) is how many spaces to insert in each interval of strings    extraNum = (L - count) % (i - last - 1); // calculate if one more space need to be inserted into the left intervals}StringBuilder str = new StringBuilder();for (int j = last; j < i; j++) {str.append(words[j]);if (j < i - 1) {// see if current string is the last string in the current row. (i - 1) is the index of last string, because words[i] makes current length > Lfor (int k = 0; k < spaceNum; k++) {str.append(" ");}if (extraNum > 0) {str.append(" ");}extraNum--;}}for (int j = str.length(); j < L; j++) {  // sometimes spaceNum, extraNum are both zero, so you need to insert spaces after the string.str.append(" ");}res.add(str.toString());count = 0;last = i;}count += words[i].length();}StringBuilder str = new StringBuilder();for (int i = last; i < words.length; i++) {str.append(words[i]);if (str.length() < L)str.append(" ");}for (int i = str.length(); i < L; i++) {str.append(" ");}res.add(str.toString());return res;}}