Add algorithm in README.md

Techie Sky · Techie Sky · commit 9bc05a9b2188 · 2021-09-09T07:58:58.000+05:30
diff --git a/README.md b/README.md
@@ -168,6 +168,35 @@ Inspired by [30 seconds of code](https://github.com/Chalarangelo/30-seconds-of-c
   }
 ```
 
+### CountingSort
+```java
+  public static void countingSort(int[] arr) {
+    var max = Arrays.stream(arr).max().getAsInt();
+
+    var count = new int[max + 1];
+
+    for (var num : arr) {
+      count[num]++;
+    }
+
+    for (var i = 1; i <= max; i++) {
+      count[i] += count[i - 1];
+    }
+
+    var sorted = new int[arr.length];
+    for (var i = arr.length - 1; i >= 0; i--) {
+      var cur = arr[i];
+      sorted[count[cur] - 1] = cur;
+      count[cur]--;
+    }
+
+    var index = 0;
+    for (var num : sorted) {
+      arr[index++] = num;
+    }
+  }
+```
+
 ## Array
 
 ### Generic two array concatenation
