save project

binary_search.py

@@ -2,19 +2,21 @@
 num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
 num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
 high=len(num_list)-1
 high=len(num_list)-1
 low=0
 low=0
-mid=(high+low)//2
-n=20
+
+n=2
     
     
-while True:
-    if num_list[mid]<n:
-        low=mid+1
+while low <= high:
+    mid = (low+high)//2
+    guess = num_list[mid]
+    if guess==n:
+        print('找到'+str(n)+'了，索引为'+str(mid))
+        break 
         
         
-    elif num_list[mid]>n:
+    elif guess>n:
         high=mid-1
         high=mid-1
         
         
-    elif num_list[mid]==n:
-        print('找到'+str(n)+'了，索引为'+'str(mid)')
-        break 
-    elif high<=low:
-        print('找不到'+'n'+',嘿嘿嘿～')
-        break
+    elif guess<n:
+        low = mid +1
+    if high<low:
+        print('找不到')
+