added count sort

basic_algo/count_sort.java

@@ -0,0 +1,35 @@
+package basic_algo;
+
+import java.util.*;
+
+public class count_sort {
+    static int[] count_sort_(int nums[]) {
+        int min = Integer.MAX_VALUE;
+        int max = Integer.MIN_VALUE;
+        for (int val : nums)
+            max = Math.max(max, val);
+        for (int val : nums)
+            min = Math.min(min, val);
+
+        int range = max - min + 1;
+        int freq_cnt[] = new int[range];
+        int res[] = new int[nums.length];
+        for (int val : nums)
+            freq_cnt[val - min]++;
+        for (int i = 1; i < nums.length; i++)
+            freq_cnt[i] += freq_cnt[i - 1];
+        for (int i = nums.length - 1; i >= 0; i--) {
+            int val = nums[i];
+            int pos = freq_cnt[val - min];
+            res[pos - 1] = val;
+            freq_cnt[val - min]--;
+        }
+        return res;
+    }
+
+    public static void main(String args[]) {
+        int arr[] = { 1, 1, 3, 1, 2, 5, 6, 1, 4, 1, 2, 6, 4, 3 };
+        int res[] = count_sort_(arr);
+        System.out.println(Arrays.toString(res));
+    }
+}