Counting Sort algorithm in C

C/algorithms/sorting/counting_sort.c

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+//C code to implement counting sort
+
+//Counting Sort is a simple sorting algorithm that works by counting how many times each element appears in the input array instead of comparing them directly. 
+// First, it finds the largest value in the array to determine the range of numbers. 
+// Then, it creates a separate “count” array, where each index represents a number from the input and stores how many times that number occurs. 
+// After counting all elements, the algorithm reconstructs the sorted array by writing each number according to its frequency. 
+// This process efficiently sorts the elements in "O(n + k)" time, where n is the number of elements and *k* is the range of possible values. 
+// Counting Sort is best suited for sorting integers or small-range data.
+
+//Time Complexity= O(n+max), same for all cases
+//Space Complexity= O(max), same for all cases
+
+//Drawback: Not suitable for large set of data
+
+//Test Cases:
+
+//Test Case 1: Basic:
+//Input:
+//5
+//4 2 1 3 5
+//Output:
+//5 4 3 2 1
+
+//Test Case 2: Repeated Numbers
+//Input:
+//8
+//3 1 4 3 2 3 5 2
+//Output:
+//5 4 3 3 3 2 2 1
+
+//Test Case 3: Already Sorted (Descending)
+//Input:
+//5
+//9 8 7 6 5
+//Output:
+//9 8 7 6 5
+
+//Test Case 4: All Elements Same
+//Input:
+//6
+//0 3 1 0 2 5
+//Output:
+//5 3 2 1 0 0
+
+//Code
+#include<stdio.h>
+int main()
+{
+    //input array
+    int n;
+    scanf("%d",&n);
+    int arr[n];
+    for(int i=0;i<n;i++)
+    {
+        scanf("%d",&arr[i]);
+    }
+    //find max element
+    int max=arr[0];
+    for(int i=0;i<n;i++)
+    {
+        if(arr[i]>max)
+        {
+            max=arr[i];
+        }
+    }
+    //initialize count array
+    int countArr[max+1];
+    for(int i=0;i<max+1;i++)
+    {
+        countArr[i]=0;
+    }
+    //count frequencies
+    for(int i=0;i<n;i++)
+    {
+        countArr[arr[i]]++;
+    }
+    //Build sorted array in ascending order
+    int x=0;
+    for(int i=0;i<max+1;i++)
+    {
+        while(countArr[i]>0)
+        {
+            arr[x]=i;
+            countArr[i]--;
+            x++;
+        }
+    }
+    //Print the array
+    for(int i=0;i<n;i++)
+    {
+        printf("%d ",arr[i]);
+    }
+    return 0;
+}