Create RadixSort.cpp

S-SearchingAlgorithms/RadixSort.cpp

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+// C++ implementation of Radix Sort
+
+#include <iostream>
+using namespace std;
+
+// A utility function to get maximum value in arr[]
+int getMax(int arr[], int n)
+{
+	int mx = arr[0];
+	for (int i = 1; i < n; i++)
+		if (arr[i] > mx)
+			mx = arr[i];
+	return mx;
+}
+
+// A function to do counting sort of arr[] according to
+// the digit represented by exp.
+void countSort(int arr[], int n, int exp)
+{
+	int output[n]; // output array
+	int i, count[10] = { 0 };
+
+	// Store count of occurrences in count[]
+	for (i = 0; i < n; i++)
+		count[(arr[i] / exp) % 10]++;
+
+	// Change count[i] so that count[i] now contains actual
+	// position of this digit in output[]
+	for (i = 1; i < 10; i++)
+		count[i] += count[i - 1];
+
+	// Build the output array
+	for (i = n - 1; i >= 0; i--) {
+		output[count[(arr[i] / exp) % 10] - 1] = arr[i];
+		count[(arr[i] / exp) % 10]--;
+	}
+
+	// Copy the output array to arr[], so that arr[] now
+	// contains sorted numbers according to current digit
+	for (i = 0; i < n; i++)
+		arr[i] = output[i];
+}
+
+// The main function to that sorts arr[] of size n using
+// Radix Sort
+void radixsort(int arr[], int n)
+{
+	// Find the maximum number to know number of digits
+	int m = getMax(arr, n);
+
+	// Do counting sort for every digit. Note that instead
+	// of passing digit number, exp is passed. exp is 10^i
+	// where i is current digit number
+	for (int exp = 1; m / exp > 0; exp *= 10)
+		countSort(arr, n, exp);
+}
+
+// A utility function to print an array
+void print(int arr[], int n)
+{
+	for (int i = 0; i < n; i++)
+		cout << arr[i] << " ";
+}
+
+// Driver Code
+int main()
+{
+	int arr[] = { 170, 45, 75, 90, 802, 24, 2, 66 };
+	int n = sizeof(arr) / sizeof(arr[0]);
+
+	// Function Call
+	radixsort(arr, n);
+	print(arr, n);
+	return 0;
+}