Changes for Leetcode problems

Author: whichrakesh

Google Questions/Word Squares.js

@@ -0,0 +1,43 @@
+// https://leetcode.com/explore/interview/card/google/62/recursion-4/370/
+
+/**
+ * @param {string[]} words
+ * @return {string[][]}
+ */
+var wordSquares = function(words) {
+    let wordMap = {};
+    for(let word of words){
+        for(let i in word){
+            let substr = word.substr(0, i);
+            if(!wordMap.hasOwnProperty(substr)){
+                wordMap[substr] = [];
+            }
+            wordMap[substr].push(word);
+        }
+    }
+    
+    let squares = [];
+    for(let word of words){
+        squares = [...squares, ...findSquares(wordMap, [word], word.length)];
+    }
+    return squares;
+};
+
+var findSquares = function(wordsMap, curSquare, wordLength) {
+    let i = curSquare.length;
+    if(i >= wordLength){
+        return [curSquare];
+    }
+    let nextWordStart = curSquare.map(w => w[i]).join('');
+    
+    if(wordsMap.hasOwnProperty(nextWordStart)){
+        let squares = [];
+        for(let word of wordsMap[nextWordStart]){
+            //if(curSquare.indexOf(word) == -1){
+                squares = [...squares, ...findSquares(wordsMap, [...curSquare, word], wordLength)];   
+            //}
+        }
+        return squares;
+    }
+    return [];
+}