diff --git a/QuickSort.py b/QuickSort.py
index cd8a673..59b0972 100644
--- a/QuickSort.py
+++ b/QuickSort.py
@@ -1,3 +1,5 @@
+# coding: utf-8
+
 def quickSort(alist):
     quickSortHelper(alist, 0, len(alist)-1)
 
@@ -16,9 +18,9 @@ def partition(alist, first, last):
     done = False
 
     while not done:
-        while alist[leftmark] <= pivotvlue and leftmark <= rightmark:
+        while leftmark <= rightmark and alist[leftmark] <= pivotvlue: # bugfix: 先比较index, 不然数组会越界
             leftmark += 1
-        while alist[rightmark] >= pivotvlue and rightmark >= leftmark:
+        while rightmark >= leftmark and alist[rightmark] >= pivotvlue:
             rightmark -= 1
 
         if leftmark > rightmark:
@@ -32,3 +34,13 @@ def partition(alist, first, last):
 alist2 = [1]
 quickSort(alist2)
 print(alist2)
+
+
+if __name__ == "__main__":
+    test_data = [3,2,111,3,-1,0,0,1,0,2,4]
+
+    res_stable = sorted(test_data)
+    quickSort(test_data)
+    print(test_data)
+    print(res_stable)
+    assert all(map(lambda x: x[0] == x[1], zip(res_stable, test_data)))
\ No newline at end of file
diff --git "a/Target Offer/\344\272\214\347\273\264\346\225\260\347\273\204\346\237\245\346\211\276.py" "b/Target Offer/\344\272\214\347\273\264\346\225\260\347\273\204\346\237\245\346\211\276.py"
index 3d05286..81239fd 100644
--- "a/Target Offer/\344\272\214\347\273\264\346\225\260\347\273\204\346\237\245\346\211\276.py"	
+++ "b/Target Offer/\344\272\214\347\273\264\346\225\260\347\273\204\346\237\245\346\211\276.py"	
@@ -29,6 +29,8 @@ def Find(self, array, target):
         # 判断非法输入
         # 可以换成 isinstance(target, (int, float)) 进行判断
         if type(target) == float and type(array[0][0]) == int:
+            if int(target) == target:
+                return False
             target = int(target)
         elif type(target) == int and type(array[0][0]) == float:
             target = float(int)
diff --git "a/Target Offer/\346\233\277\346\215\242\347\251\272\346\240\274.py" "b/Target Offer/\346\233\277\346\215\242\347\251\272\346\240\274.py"
index 72e50f2..bd15a41 100644
--- "a/Target Offer/\346\233\277\346\215\242\347\251\272\346\240\274.py"	
+++ "b/Target Offer/\346\233\277\346\215\242\347\251\272\346\240\274.py"	
@@ -6,6 +6,20 @@
 # -*- coding:utf-8 -*-
 class Solution:
     # s 源字符串
+    
+    # 使用append一次遍历即可替换
+    # 由于list的append是O(1)的时间复杂度，除了扩容所导致的时间损耗，该算法复杂度为O(n)
+    def replaceSpaceByAppend(self, s):
+        string = list(string)
+	    stringReplace = []
+	    for item in string:
+		    if item == ' ':
+			    stringReplace.append('%')
+			    stringReplace.append('2')
+			    stringReplace.append('0')
+		    else:
+			    stringReplace.append(item)
+	    return "".join(stringReplace)
 
     # 创建新的字符串进行替换
     def replaceSpace1(self, s):