Create Counting Sort .cpp

data structures/cpp/Counting Sort .cpp

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+// Counting sort in C++ programming
+
+#include <iostream>
+using namespace std;
+
+void countSort(int array[], int size) 
+{
+
+    /* The size of count must be at least the (max+1) but
+        we cannot assign declare it as int count(max+1) in C++ as
+        it does not support dynamic memory allocation.
+        So, its size is provided statically. */
+
+    int output[1000000]; // taking the numerical limit to be 10^6
+    int count[1000000]; // taking the numerical limit to be 10^6
+    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;
+
+}
+
+// Driver code
+int main() 
+{
+    // Creating a Sample Array in C++
+    int array[] = {4, 32, 2, 83, 3, 321, 145556};
+
+    // Finding the size of the array
+    int n = sizeof(array) / sizeof(array[0]);
+
+    // Calling the Counting Sort Algorithm function
+    countSort(array, n);
+
+    // Printing the Sorted Array
+    printArray(array, n);
+
+}