From cdec985db1eceeb708def5ce8166e4170d1639a3 Mon Sep 17 00:00:00 2001
From: kde0820 <kde0820@naver.com>
Date: Sat, 2 Dec 2017 09:33:23 +0900
Subject: [PATCH] C quicksort (#44)

* Add C example for recursion

* Add loop_sum in c

* Add recursive_sum in c

* Add quicksort in c
---
 04_quicksort/c/01_loop_sum.c      | 16 +++++++++++++
 04_quicksort/c/02_recursive_sum.c | 14 +++++++++++
 04_quicksort/c/05_quicksort.c     | 40 +++++++++++++++++++++++++++++++
 3 files changed, 70 insertions(+)
 create mode 100644 04_quicksort/c/01_loop_sum.c
 create mode 100644 04_quicksort/c/02_recursive_sum.c
 create mode 100644 04_quicksort/c/05_quicksort.c

diff --git a/04_quicksort/c/01_loop_sum.c b/04_quicksort/c/01_loop_sum.c
new file mode 100644
index 0000000..81763ee
--- /dev/null
+++ b/04_quicksort/c/01_loop_sum.c
@@ -0,0 +1,16 @@
+#include <stdio.h>
+
+int sum(int *arr, int size) {
+	int total = 0;
+	for (int i = 0; i < size; i++) {
+		total += arr[i];
+	}
+	return total;
+}
+
+int main(void) {
+	int arr[4] = { 1,2,3,4 };
+	printf("%d", sum(arr, 4));
+
+	return 0;
+}
\ No newline at end of file
diff --git a/04_quicksort/c/02_recursive_sum.c b/04_quicksort/c/02_recursive_sum.c
new file mode 100644
index 0000000..28aa8bf
--- /dev/null
+++ b/04_quicksort/c/02_recursive_sum.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+int sum(int *arr, int index, int size) {
+	if (index == size)
+		return 0;
+	return arr[index] + sum(arr, index + 1, 4);
+}
+
+int main(void) {
+	int arr[4] = { 1,2,3,4 };
+	printf("%d", sum(arr, 0, 4));
+
+	return 0;
+}
\ No newline at end of file
diff --git a/04_quicksort/c/05_quicksort.c b/04_quicksort/c/05_quicksort.c
new file mode 100644
index 0000000..b9b5d7c
--- /dev/null
+++ b/04_quicksort/c/05_quicksort.c
@@ -0,0 +1,40 @@
+#include <stdio.h>
+
+// Quick Sort
+void quick_sort(int *array, int start, int end) {
+	if (start < end) {
+		int q = partition(array, start, end);
+		quick_sort(array, start, q - 1);
+		quick_sort(array, q + 1, end);
+	}
+}
+// Partition by pivot
+int partition(int *array, int start, int end) {
+	int pivot = array[end];
+	int i = start - 1;
+	int temp = 0;
+	for (int j = start; j < end; j++) {
+		if (array[j] <= pivot) {
+			i++;
+			temp = array[i];
+			array[i] = array[j];
+			array[j] = temp;
+		}
+	}
+	temp = array[i + 1];
+	array[i + 1] = array[end];
+	array[end] = temp;
+
+	return i + 1;
+}
+
+int main(void) {
+	int arr[4] = {10, 5, 2, 3};
+	quick_sort(arr, 0, 3);
+	// Print result
+	for (int i = 0; i < 4; i++) {
+		printf("%d ", arr[i]);
+	}
+
+	return 0;
+}
\ No newline at end of file