From 780738068dcace40471caeccdb46bc772ec281a6 Mon Sep 17 00:00:00 2001
From: hariprasetia <hari.prasetia@gmail.com>
Date: Tue, 8 Oct 2019 15:59:17 +0700
Subject: [PATCH] add quick sort using c

---
 hariprasetia_quicksort.c | 66 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 hariprasetia_quicksort.c

diff --git a/hariprasetia_quicksort.c b/hariprasetia_quicksort.c
new file mode 100644
index 0000000..3e8086c
--- /dev/null
+++ b/hariprasetia_quicksort.c
@@ -0,0 +1,66 @@
+# include <stdio.h>
+
+// to swap two numbers
+void swap(int* a, int* b)
+{
+    int t = *a;
+    *a = *b;
+    *b = t;
+}
+
+/*
+    a[] is the array, p is starting index, that is 0,
+    and r is the last index of array.
+*/
+void quicksort(int a[], int p, int r)
+{
+    if(p < r)
+    {
+        int q;
+        q = partition(a, p, r);
+        quicksort(a, p, q);
+        quicksort(a, q+1, r);
+    }
+}
+
+int partition (int a[], int low, int high)
+{
+    int pivot = arr[high];  // selecting last element as pivot
+    int i = (low - 1);  // index of smaller element
+
+    for (int j = low; j <= high- 1; j++)
+    {
+        // If current element is smaller than or equal to pivot
+        if (arr[j] <= pivot)
+        {
+            i++;    // increment index of smaller element
+            swap(&arr[i], &arr[j]);
+        }
+    }
+    swap(&arr[i + 1], &arr[high]);
+    return (i + 1);
+}
+
+// function to print the array
+void printArray(int a[], int size)
+{
+    int i;
+    for (i=0; i < size; i++)
+    {
+        printf("%d ", a[i]);
+    }
+    printf("\n");
+}
+
+int main()
+{
+    int arr[] = {9, 7, 5, 11, 12, 2, 14, 3, 10, 6};
+    int n = sizeof(arr)/sizeof(arr[0]);
+
+    // call quickSort function
+    quickSort(arr, 0, n-1);
+
+    printf("Sorted array: n");
+    printArray(arr, n);
+    return 0;
+}