Added CountingSort.cpp

counting_sort/CountingSort.cpp

@@ -0,0 +1,57 @@
+#include <iostream>
+using namespace std;
+
+void countSort(int array[], int size) {
+ // We will provide static allocation to the output array
+  int output[10];
+  int count[10];
+  int max = array[0];
+
+  // Find the largest element of the array
+  for (int i = 1; i < size; i++) {
+    if (array[i] > max)
+      max = array[i];
+  }
+
+  // Initialize count array with all zeros.
+  for (int i = 0; i <= max; ++i) {
+    count[i] = 0;
+  }
+
+  // Store the count of each element
+  for (int i = 0; i < size; i++) {
+    count[array[i]]++;
+  }
+
+  // Store the cummulative count of each array
+  for (int i = 1; i <= max; i++) {
+    count[i] += count[i - 1];
+  }
+
+  // Find the index of each element of the original array in count array, and
+  // place the elements in output array
+  for (int i = size - 1; i >= 0; i--) {
+    output[count[array[i]] - 1] = array[i];
+    count[array[i]]--;
+  }
+
+  // Copy the sorted elements into original array
+  for (int i = 0; i < size; i++) {
+    array[i] = output[i];
+  }
+}
+
+// Function to print an array
+void printArray(int array[], int size) {
+  for (int i = 0; i < size; i++)
+    cout << array[i] << " ";
+  cout << endl;
+}
+
+
+int main() {
+  int array[] = {4, 2, 2, 8, 3, 3, 1};
+  int n = sizeof(array) / sizeof(array[0]);
+  countSort(array, n);
+  printArray(array, n);
+}