Add counting sort algorithm in JavaScript (#911)

Author: tinniaru3005

Javascript/Algorithms/counting-sort.js

@@ -0,0 +1,27 @@
+const countingSort = (inputArr, n = inputArr.length) => {
+    let k = Math.max(...inputArr);
+    let t;
+    const temp = new Array(k + 1).fill(0);
+    
+    for(let i = 0; i < n; i++){
+      t = inputArr[i];
+      temp[t]++;
+    }
+  
+    for(let i = 1; i <= k; i++){
+      
+      temp[i] = temp[i] + temp[i - 1];  
+    }
+    
+    const outputArr = new Array(n).fill(0);
+    
+    for(let i = n - 1; i >= 0; i--) {
+    
+      t = inputArr[i];
+      outputArr[temp[t] - 1] = t;  
+          
+      temp[t] = temp[t] - 1;		
+     }
+    
+    return outputArr;
+}