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
 # 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]
 num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
+low=0
+high=len(num_list)-1
+num=21
+while high>=low:
+    mid=(high+low)//2
+    if num == num_list[mid]:
+        print('找到了，索引是'+str(mid))
+        exit()
+    elif num <num_list[mid]:
+        high=mid-1
+    else:
+        low=mid+1
+if high<low:
+    print('没查到')
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