added countSort.cpp

implementation of count sort in c++

Author: neo22222

C++/countSort.cpp

@@ -0,0 +1,40 @@
+#include <bits/stdc++.h>
+using namespace std;
+void countsort(int arr[], int n)
+{
+    int maxElement = arr[0];
+    for (int i = 0; i < n; i++)
+    {
+        maxElement = max(maxElement, arr[i]);
+    }
+
+    int count[10] = {0};
+    for (int i = 0; i < n; i++)
+    {
+        count[arr[i]]++;
+    }
+
+    for (int i = 1; i <= maxElement; i++)
+    {
+        count[i] += count[i - 1];
+    }
+    int output[n];
+    for (int i = n - 1; i >= 0; i--)
+    {
+        output[--count[arr[i]]] = arr[i]; // take count of arr[i] and first decrement it
+    }
+    for (int i = 0; i < n; i++)
+    {
+        arr[i] = output[i];
+    }
+}
+
+int main()
+{
+    int arr[] = {1, 3, 2, 3, 4, 1, 6, 4, 3};
+    countsort(arr, 9);
+    for (int i = 0; i < 9; i++)
+    {
+        cout << arr[i] << " ";
+    }
+}