12.4

Author: huangyt39

464.py

@@ -0,0 +1,51 @@
+class Solution:
+    """
+    @param A: an integer array
+    @return: nothing
+    """
+    def sortIntegers2(self, A):
+        # write your code here
+        if len(A) <= 0:
+            return []
+        return Solution.subsort(1, A)
+        
+    def subsort(self, arr):
+        if len(arr) <= 1:
+            return arr
+        if len(arr) == 2:
+            if(arr[0] > arr[1]):
+                return [arr[1], arr[0]]
+            else:
+                return arr
+        else:
+            size = len(arr)
+            return Solution.merge(1, Solution.subsort(1, arr[:size//2]), Solution.subsort(1, arr[size//2:]))
+
+    def merge(self, arr1, arr2):
+        res = []
+        if len(arr1) == 0:
+            return arr2
+        if len(arr2) == 0:
+            return arr1
+        i, j = 0, 0
+        while i < len(arr1) and j < len(arr2):
+            if arr1[i] < arr2[j]:
+                res.append(arr1[i])
+                i += 1
+            else :
+                res.append(arr2[j])
+                j += 1
+        if i == len(arr1):
+            while j < len(arr2):
+                res.append(arr2[j])
+                j += 1
+        if j == len(arr2):
+            while i < len(arr1):
+                res.append(arr1[i])
+                i += 1
+        return res
+
+print(Solution.sortIntegers2(1, [3, 2, 1, 4, 5, 7, 6, 8]))
+print(Solution.sortIntegers2(1, []))
+print(Solution.sortIntegers2(1, [3, 2, 1, 4, 5, 7, 6]))
+print(Solution.sortIntegers2(1, [3,2,1,4,5]))