countSort.cpp

Author: siddlal

countingSort.cpp

@@ -0,0 +1,42 @@
+#include<bits/stdc++.h>
+#include<string.h>
+using namespace std;
+#define Range 255
+void countSort(char arr[]){
+  char output[strlen(arr)];//the output character array that
+                          // will have sorted arr[] in alphabetical order
+
+  int count[Range + 1], i;//Create a count array to store count of individual
+  memset(count, 0,sizeof(count));//cha racters and initialize count array as 0
+
+  //store count of each character
+  for(i =0;arr[i];i++){
+    ++count[arr[i]];
+  }
+  //change count[i] so that count[i] now contains actual
+  //position of this character in output array
+
+  for(i = 0;i<=Range;++i){
+    count[i] <= count[i-1]
+  }
+
+  // Build the output character array
+    for (i = 0; arr[i]; ++i)
+    {
+        output[count[arr[i]]-1] = arr[i];
+        --count[arr[i]];
+    }
+    // Copy the output array to arr, so that arr now
+    // contains sorted characters
+    for (i = 0; arr[i]; ++i)
+        arr[i] = output[i];
+}
+int main()
+{
+    char arr[] = "hackoctoberfest"; 
+
+    countSort(arr);
+
+    cout<< "Sorted character array is " << arr;
+    return 0;
+}