From d9790182c8192aee50e1a687aa1dac1ca67d4c01 Mon Sep 17 00:00:00 2001
From: heimoshuiyu <heimoshuiyu@gmail.com>
Date: Wed, 28 Apr 2021 22:02:17 +0800
Subject: [PATCH] week9 heapsort and quicksort compare

---
 week9/T8.c | 113 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 week9/T8.h |  16 ++++++++
 2 files changed, 129 insertions(+)
 create mode 100644 week9/T8.c
 create mode 100644 week9/T8.h

diff --git a/week9/T8.c b/week9/T8.c
new file mode 100644
index 0000000..f73ce0c
--- /dev/null
+++ b/week9/T8.c
@@ -0,0 +1,113 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include "T8.h"
+
+int main() {
+	int size = 5000000;
+	clock_t start_time, end_time;
+
+	int *A1 = (int *)malloc(sizeof(int) * size);
+	if (A1 == NULL) {
+		printf("Fatal: Can not allocate memory of A1 with size=%d\n", size);
+		exit(1);
+	}
+
+	int *A2 = (int *)malloc(sizeof(int) * size);
+	if (A2 == NULL) {
+		printf("Fatal: Can not allocate memory of A2 with size=%d\n", size);
+		exit(1);
+	}
+
+	/* generate random number */
+	for (int i = 0; i < size; i++) {
+		A1[i] = A2[i] = rand();
+	}
+
+	printf("Testing HeapSort function ... ");
+	start_time = clock();
+	HeapSort(A1, size);
+	end_time = clock();
+	printf("%s\n", Check(A1, size) ? "pass" : "failed");
+	PrintTimeDuration(start_time, end_time);
+
+	printf("Testing QuickSort function ... ");
+	start_time = clock();
+	QuickSort(A2, 0, size - 1);
+	end_time = clock();
+	printf("%s\n", Check(A1, size) ? "pass" : "failed");
+	PrintTimeDuration(start_time, end_time);
+
+	return 0;
+}
+
+bool Check(int *A, int size) {
+	for (int i = 0; i < size - 1; i++) {
+		if (A[i] > A[i + 1]) {
+			return false;
+		}
+	}
+	return true;
+}
+
+void QuickSort(int *A, int left, int right) {
+	if (left >= right) {
+		return;
+	}
+	int pi = Partition(A, left, right);
+	QuickSort(A, left, pi - 1);
+	QuickSort(A, pi + 1, right);
+}
+
+int Partition(int *A, int left, int right) {
+	int pivot = A[right];
+	int i = left - 1;
+	for (int j = left; j < right; j++) {
+		if (A[j] < pivot) {
+			Swap(&A[++i], &A[j]);
+		}
+	}
+	Swap(&A[++i], &A[right]);
+	return i;
+}
+
+void HeapSort(int *A, int n) {
+	int i;
+	for (i = n / 2; i >= 0; i--) {
+		PercDown(A, i, n);
+	}
+	for (i = n - 1; i > 0; i--) {
+		Swap(&A[0], &A[i]);
+		PercDown(A, 0, i);
+	}
+}
+
+void PercDown(int *A, int i, int n) {
+	int child, tmp;
+
+	for (tmp = A[i]; (2 * i + 1) < n; i = child) {
+		child = 2 * i + 1;
+		if (child != n - 1 && A[child + 1] > A[child]) {
+			child++;
+		}
+		if (tmp < A[child]) {
+			A[i] = A[child];
+		} else {
+			break;
+		}
+	}
+	A[i] = tmp;
+}
+
+void Swap(int *a, int *b) {
+	int tmp = *a;
+	*a = *b;
+	*b = tmp;
+}
+
+void PrintTimeDuration(clock_t start_time, clock_t end_time) {
+	printf("Time cost: %ld ms\n", (end_time - start_time) / (CLOCKS_PER_SEC / 1000));
+}
+
diff --git a/week9/T8.h b/week9/T8.h
new file mode 100644
index 0000000..4b3435a
--- /dev/null
+++ b/week9/T8.h
@@ -0,0 +1,16 @@
+#include <time.h>
+
+
+void QuickSort(int *A, int left, int right);
+
+int Partition(int *A, int left, int right);
+
+void HeapSort(int *A, int n);
+
+void PercDown(int *A, int i, int n);
+
+bool Check(int *A, int size);
+
+void Swap(int *a, int *b);
+
+void PrintTimeDuration(clock_t start_time, clock_t end_time);