maximum product of word length

Author: chen0040

.idea/workspace.xml

@@ -387,3 +387,4 @@ codes may not be optimized
 1. [Serialize and Deserialize BST](https://leetcode.com/problems/serialize-and-deserialize-bst/description/)
 1. [Find Duplicate Subtrees](https://leetcode.com/problems/find-duplicate-subtrees/description/)
 1. [Longest Absolute File Path](https://leetcode.com/problems/longest-absolute-file-path/description/)
+1. [Maximum Product of Word Length](https://leetcode.com/problems/maximum-product-of-word-lengths/description/)

README.md

@@ -0,0 +1,39 @@
+package com.github.chen0040.leetcode.day18.medium;
+
+
+/**
+ * Created by xschen on 13/8/2017.
+ *
+ * link: https://leetcode.com/problems/maximum-product-of-word-lengths/description/
+ */
+public class MaximumProductOfWordLength {
+   public class Solution {
+      public int maxProduct(String[] words) {
+         int[][] vectors = new int[words.length][];
+         for(int i=0; i < words.length; ++i) {
+            String word = words[i];
+            int[] vec = new int[26];
+            for(int j = 0; j < word.length(); ++j){
+               int d = (int)word.charAt(j) - (int)'a';
+               vec[d] = 1;
+            }
+            vectors[i] = vec;
+         }
+
+         int maxLength = 0;
+         for(int i=0; i < words.length; ++i) {
+            for(int j=i+1; j < words.length; ++j){
+               int dp = 0;
+               for(int k=0; k < 26; ++k){
+                  dp += vectors[i][k] * vectors[j][k];
+               }
+               if(dp == 0) {
+                  maxLength = Math.max(maxLength, words[i].length() * words[j].length());
+               }
+            }
+         }
+
+         return maxLength;
+      }
+   }
+}