save project

binary_search.py

 # 使用二分查找法，找出9和20在列表里面的索引
-num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
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+num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
+num = 11
+
+def a (alist,num):
+    low = 0
+    high=len(alist)-1
+    while low <= high:
+        mid = (low+high)//2
+        guess = num_list[mid]
+        if guess == num:
+            return mid
+        elif guess < num:
+            high = mid-1
+        else:
+            low=mid+1        
+    return None
+b = a (num_list,8)
+print(b)
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