finish 68

Author: BaffinLee

68. Text Justification.js

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+/**
+ * 68. Text Justification
+ * 
+ * Given an array of words and a width maxWidth, format the text such that each line has exactly maxWidth 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 exactly maxWidth 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.
+ * 
+ * Note:
+ * 
+ * A word is defined as a character sequence consisting of non-space characters only.
+ * Each word's length is guaranteed to be greater than 0 and not exceed maxWidth.
+ * The input array words contains at least one word.
+ * 
+ * Example 1:
+ * 
+ * Input:
+ * words = ["This", "is", "an", "example", "of", "text", "justification."]
+ * maxWidth = 16
+ * Output:
+ * [
+ *    "This    is    an",
+ *    "example  of text",
+ *    "justification.  "
+ * ]
+ * Example 2:
+ * 
+ * Input:
+ * words = ["What","must","be","acknowledgment","shall","be"]
+ * maxWidth = 16
+ * Output:
+ * [
+ *   "What   must   be",
+ *   "acknowledgment  ",
+ *   "shall be        "
+ * ]
+ * Explanation: Note that the last line is "shall be    " instead of "shall     be",
+ *              because the last line must be left-justified instead of fully-justified.
+ *              Note that the second line is also left-justified becase it contains only one word.
+ * Example 3:
+ * 
+ * Input:
+ * words = ["Science","is","what","we","understand","well","enough","to","explain",
+ *          "to","a","computer.","Art","is","everything","else","we","do"]
+ * maxWidth = 20
+ * Output:
+ * [
+ *   "Science  is  what we",
+ *   "understand      well",
+ *   "enough to explain to",
+ * 	 "a  computer.  Art is",
+ *   "everything  else  we",
+ *   "do                  "
+ * ]
+ */
+
+/**
+ * @param {string[]} words
+ * @param {number} maxWidth
+ * @return {string[]}
+ */
+var fullJustify = function(words, maxWidth) {
+	var len = words.length;
+	var arr = [];
+	var width = 0;
+	var item = null;
+	var addLen = 0;
+	var res = [];
+
+	for (var i = 0; i < len; i++) {
+			item = words[i];
+			addLen = width === 0 ? item.length : (item.length + 1);
+			
+			if (width + addLen > maxWidth) {
+					res.push(helper(arr, maxWidth - width, false));
+					arr = [];
+					width = 0;
+					addLen = item.length;
+			}
+			
+			arr.push(item);
+			width += addLen;
+	}
+
+	res.push(helper(arr, maxWidth - width, true));
+
+	return res;
+};
+
+var helper = function (arr, left, isLast) {
+	var len = arr.length;
+	var num = 0;
+	var rem = 0;
+	var res = '';
+	
+	if (len === 1 || isLast) {
+			return arr.join(' ') + ' '.repeat(left);
+	}
+
+	num = Math.floor(left / (len - 1));
+	rem = left % (len - 1);
+	for (var i = 0; i < len; i++) {
+			res += arr[i];
+			if (i < len - 1) res += ' '.repeat(num + 1);
+			if (i < rem) res += ' ';
+	}
+
+	return res;
+};