Step 8: Mergesort

MergesortMulti.c

@@ -0,0 +1,103 @@
+#include "cse356header.h"
+
+int numbers[1000000], temp[1000000];
+
+struct arg_struct {
+	int le;
+	int ri;
+};
+
+void *m_sort(void *args);
+void merge(int left, int mid, int right);
+
+void mergeSort(int array_size)
+{
+  struct arg_struct aus;
+  aus.le = 0; aus.ri = array_size - 1;
+  pthread_t mth;
+  pthread_create(&mth, NULL, m_sort, &aus);
+  pthread_join(mth, NULL);
+}
+
+
+void *m_sort(void *args)
+{
+  struct arg_struct *aus = (struct arg_struct *) args;
+  int mid, left = aus->le, right = aus->ri;
+
+  if (right > left)
+  {
+    mid = (right + left) / 2;
+	pthread_t lth, rth;
+	struct arg_struct lst, rst;
+	lst.le = left; lst.ri = mid;
+	rst.le = mid + 1; rst.ri = right;
+
+    pthread_create(&lth, NULL, m_sort, &lst);
+    pthread_create(&rth, NULL, m_sort, &rst);
+
+	pthread_join(lth, NULL);
+	pthread_join(rth, NULL);
+    merge(left, mid+1, right);
+  }
+  pthread_exit(0);
+}
+
+void merge(int left, int mid, int right)
+{
+  int i, left_end, num_elements, temp_pos;
+
+  left_end = mid - 1;
+  temp_pos = left;
+  num_elements = right - left + 1;
+
+  while ((left <= left_end) && (mid <= right))
+  {
+    if (numbers[left] <= numbers[mid])
+    {
+      temp[temp_pos] = numbers[left];
+      temp_pos = temp_pos + 1;
+      left = left +1;
+    }
+    else
+    {
+      temp[temp_pos] = numbers[mid];
+      temp_pos = temp_pos + 1;
+      mid = mid + 1;
+    }
+  }
+
+  while (left <= left_end)
+  {
+    temp[temp_pos] = numbers[left];
+    left = left + 1;
+    temp_pos = temp_pos + 1;
+  }
+  while (mid <= right)
+  {
+    temp[temp_pos] = numbers[mid];
+    mid = mid + 1;
+    temp_pos = temp_pos + 1;
+  }
+
+  for (i=0; i <= num_elements; i++)
+  {
+    numbers[right] = temp[right];
+    right = right - 1;
+  }
+}
+
+
+main()
+{
+	freopen("data.in", "r", stdin);
+	freopen("data.out", "w", stdout);
+	int n;
+	scanf("%d", &n);
+	for(int i = 0; i < n; i++) scanf("%d", numbers + i);
+
+	mergeSort(n);
+
+	for(int i = 0; i < n; i++) printf("%d ", numbers[i]);
+	exit(0);
+}

MergesortSingle.c

@@ -0,0 +1,84 @@
+#include "cse356header.h"
+
+void m_sort(int numbers[], int temp[], int left, int right);
+void merge(int numbers[], int temp[], int left, int mid, int right);
+
+void mergeSort(int numbers[], int temp[], int array_size)
+{
+  m_sort(numbers, temp, 0, array_size - 1);
+}
+
+
+void m_sort(int numbers[], int temp[], int left, int right)
+{
+  int mid;
+
+  if (right > left)
+  {
+    mid = (right + left) / 2;
+    m_sort(numbers, temp, left, mid);
+    m_sort(numbers, temp, mid+1, right);
+
+    merge(numbers, temp, left, mid+1, right);
+  }
+}
+
+void merge(int numbers[], int temp[], int left, int mid, int right)
+{
+  int i, left_end, num_elements, tmp_pos;
+
+  left_end = mid - 1;
+  tmp_pos = left;
+  num_elements = right - left + 1;
+
+  while ((left <= left_end) && (mid <= right))
+  {
+    if (numbers[left] <= numbers[mid])
+    {
+      temp[tmp_pos] = numbers[left];
+      tmp_pos = tmp_pos + 1;
+      left = left +1;
+    }
+    else
+    {
+      temp[tmp_pos] = numbers[mid];
+      tmp_pos = tmp_pos + 1;
+      mid = mid + 1;
+    }
+  }
+
+  while (left <= left_end)
+  {
+    temp[tmp_pos] = numbers[left];
+    left = left + 1;
+    tmp_pos = tmp_pos + 1;
+  }
+  while (mid <= right)
+  {
+    temp[tmp_pos] = numbers[mid];
+    mid = mid + 1;
+    tmp_pos = tmp_pos + 1;
+  }
+
+  for (i=0; i <= num_elements; i++)
+  {
+    numbers[right] = temp[right];
+    right = right - 1;
+  }
+}
+
+int data[1000000], tmp[1000000];
+
+main()
+{
+	freopen("data.in", "r", stdin);
+	freopen("data.out", "w", stdout);
+	int n;
+	scanf("%d", &n);
+	for(int i = 0; i < n; i++) scanf("%d", data + i);
+
+	mergeSort(data, tmp, n);
+
+	for(int i = 0; i < n; i++) printf("%d ", data[i]);
+	exit(0);
+}

data.in

@@ -0,0 +1 @@
+5 3 1 2 0 4

makefile

@@ -1,4 +1,4 @@
-all: MyCopy ForkCopy PipeCopy timer MyShell MoreShell DupShell
+all: MyCopy ForkCopy PipeCopy timer MyShell MoreShell DupShell MergesortSingle MergesortMulti
 clear:
 	rm *.o
 MyCopy: MyCopy.o
@@ -29,3 +29,12 @@ DupShell: DupShell.o
 	g++ DupShell.o -o DupShell
 DupShell.o:
 	g++ -c DupShell.c
+MergesortSingle: MergesortSingle.o
+	g++ MergesortSingle.o -o MergesortSingle
+MergesortSingle.o:
+	g++ -c MergesortSingle.c 
+MergesortMulti: MergesortMulti.o
+	g++ -lpthread MergesortMulti.o -o MergesortMulti
+MergesortMulti.o:
+	g++ -c MergesortMulti.c 
+