quicksort

quicksort.c

@@ -0,0 +1,67 @@
+/*algorithm quicksort(A, lo, hi) is 
+  // Ensure indices are in correct order
+  if lo >= hi || lo < 0 then 
+    return
+    
+  // Partition array and get the pivot index
+  p := partition(A, lo, hi) 
+      
+  // Sort the two partitions
+  quicksort(A, lo, p - 1) // Left side of pivot
+  quicksort(A, p + 1, hi) // Right side of pivot
+
+// Divides array into two partitions
+algorithm partition(A, lo, hi) is 
+  pivot := A[hi] // Choose the last element as the pivot
+
+  // Temporary pivot index
+  i := lo
+
+  for j := lo to hi - 1 do 
+    // If the current element is less than or equal to the pivot
+    if A[j] <= pivot then 
+      // Swap the current element with the element at the temporary pivot index
+      swap A[i] with A[j]
+      // Move the temporary pivot index forward
+      i := i + 1
+
+  // Swap the pivot with the last element
+  swap A[i] with A[hi]
+  return i // the pivot index*/
+
+int Partition(int * array, int lo, int hi){
+  /*variables*/
+  int pivot = array[hi];
+  int tmp_ind = lo;
+  int tmp;
+  int i = 0;
+
+  /*pivots*/
+  for(i=lo; i<hi; i++){
+    if(array[i]<=pivot){
+      tmp = array[i];
+      array[i] = array[tmp_ind];
+      array[tmp_ind] = tmp;
+      tmp_ind++;
+    }
+  }
+  tmp = array[tmp_ind];
+  array[tmp_ind] = array[hi];
+  array[hi] = tmp;
+  return tmp_ind;
+}
+
+void quicksort(int * array, int lo, int hi){
+  /*variables*/
+  int p;
+
+  /*test - indices dans l'ordre*/
+  if((lo>=hi)||(lo<0)){
+    return;
+  }
+
+  p = Partition(array, lo, hi);
+
+  quicksort(array, lo, p-1);
+  quicksort(array, p+1, hi);
+}

quicksort.h

@@ -0,0 +1,7 @@
+#ifndef __QUICKSORT__
+#define __QUICKSORT__
+
+int Partition(int * array, int lo, int hi);
+void quicksort(int * array, int lo, int hi);
+
+#endif

student_rank.c

@@ -5,6 +5,7 @@
 #include <stdlib.h>
 #include "heapsort.h"
 #include "bubblesort.h"
+#include "quicksort.h"
 
 void generate_grades(int** students_array, int students_number, int grades_number)
 {
@@ -77,7 +78,7 @@ void sort_students(int** students_rank, int** students_array, int students_numbe
     	{
     	    grades[j] = students_array[j][i];
     	}
-        heapsort(grades,students_number);
+        quicksort(grades,0,students_number);
         for(j = 0; j < students_number; j++)
         {
                 students_rank[j][i] = find_rank_student(students_array[j][i],grades,students_number);