Merge pull request #497 from ubc1729/master

Indented "counting Sort" and fixed compilation errors

sorting/countingSort.c

@@ -1,28 +1,46 @@
+/*
+  > Counting sort is a sorting technique based on keys between a specific range.
+  > integer sorting algorithm
+  > Worst-case performance O(n+k)
+  > Stabilized by prefix sum array
+*/
+
 #include <stdio.h>
-  int main()
- {
- 	int i,n,l=0;
-  scanf("%d",&n);
- 	int a[n];
-  for(i=0;i<n;i++)
- 	{
-  	 	scanf("%d",&a[i]);
-  	 	if(a[i]>l)
-  	 	 l=a[i];
- 	}
- 	int b[l+1]={0};
- 	for(i=0;i<n;i++)
- 	 b[a[i]]++; //hashing number to array index
- 	for(i=0;i<(l+1);i++)
- 	{
- 		if(b[i]>0)
- 	{
- 			while(b[i]!=0) //for case when number exists more than once
- 			{
- 			printf("%d ",i); 
- 			b[i]--;
- 			}
-    	}
- 	}
- 	return 0;
- } 
+#include <string.h>
+
+int main()
+{
+    int i, n, l = 0;
+
+    printf("Enter size of array = ");
+    scanf("%d", &n);
+
+    int a[n];
+    printf("Enter %d elements in array :\n", n);
+    for(i = 0; i < n; i++)
+    {
+        scanf("%d", &a[i]);
+        if(a[i] > l)
+            l = a[i];
+    }
+
+    int b[l + 1];
+    memset(b, 0, (l + 1) * sizeof(b[0]));
+
+    for(i = 0; i < n; i++)
+        b[a[i]]++; //hashing number to array index
+
+    for(i = 0; i < (l + 1); i++) //unstable , stabilized by prefix sum array
+    {
+        if(b[i] > 0)
+        {
+            while(b[i] != 0) //for case when number exists more than once
+            {
+                printf("%d ", i);
+                b[i]--;
+            }
+        }
+    }
+
+    return 0;
+}