Added word frequency problem

Author: quazihasan

Word_Frequency/question.txt

@@ -0,0 +1,7 @@
+Given a text, find the frequency of all the words in it and print the words that are duplicates:
+"Work hard and play hard and have fun at work."
+
+answer:
+hard
+work
+and

Word_Frequency/solution.js

@@ -0,0 +1,22 @@
+function printDuplicates(inputText){
+  var frequenceCountMap = {};
+  var inputs = inputText.split(' ');
+  for(var ii = 0, len = inputs.length; ii < len; ii++){
+    var word = inputs[ii];
+    if(frequenceCountMap[word]){
+      frequenceCountMap[word] += 1;
+    }else{
+      frequenceCountMap[word] = 1;
+    }
+  }
+
+  for(var key in frequenceCountMap){
+    if(frequenceCountMap[key] > 1){
+      console.log(key);
+    }
+  }
+}
+
+var inputVal = "Work hard and play hard and have fun at work.";
+
+printDuplicates(inputVal);