Add 68_Text_Justification.java

Author: seanprashad

Strings/68_Text_Justification.java

@@ -0,0 +1,78 @@
+class Solution {
+    public List<String> fullJustify(String[] words, int maxWidth) {
+        if (words == null || words.length == 0) {
+            return Collections.emptyList();
+        }
+
+        List<String> result = new ArrayList<>();
+        int left = 0;
+
+        while (left < words.length) {
+            int right = findRight(left, words, maxWidth);
+            result.add(justify(left, right, words, maxWidth));
+            left = right + 1;
+        }
+
+        return result;
+    }
+
+    private int findRight(int left, String[] words, int maxWidth) {
+        int right = left;
+        int sum = words[right].length();
+        ++right;
+
+        while (right < words.length && (sum + 1 + words[right].length()) <= maxWidth) {
+            sum += words[right].length() + 1;
+            ++right;
+        }
+
+        return right - 1;
+    }
+
+    private String justify(int left, int right, String[] words, int maxWidth) {
+        StringBuilder sb = new StringBuilder();
+
+        if (right - left == 0) {
+            return padResult(words[left], maxWidth);
+        }
+
+        boolean isLastLine = right == words.length - 1;
+        int numOfSpaces = right - left;
+        int totalSpaces = maxWidth - wordsLength(left, right, words);
+
+        String space = isLastLine ? " " : blank(totalSpaces / numOfSpaces);
+        int remainder = isLastLine ? 0 : totalSpaces % numOfSpaces;
+
+        for (int i = left; i <= right; i++) {
+            sb.append(words[i]).append(space).append(remainder-- > 0 ? " " : "");
+        }
+
+        return padResult(sb.toString().trim(), maxWidth);
+    }
+
+    private int wordsLength(int left, int right, String[] words) {
+        int length = 0;
+
+        for (int i = left; i <= right; i++) {
+            length += words[i].length();
+        }
+
+        return length;
+    }
+
+    private String padResult(String result, int maxWidth) {
+        StringBuilder sb = new StringBuilder();
+        sb.append(result).append(blank(maxWidth - result.length()));
+
+        return sb.toString();
+    }
+
+    private String blank(int length) {
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < length; i++) {
+            sb.append(" ");
+        }
+
+        return sb.toString();
+    }
+}