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]
\ No newline at end of file
+flag=18
+
+minIndex=0
+maxIndex=len(num_list)-1
+while True:
+    mid=(minIndex+maxIndex)//2
+    if num_list[mid]==flag:
+        print("是第"+str(mid+1)+"个数")
+        break
+    elif num_list[mid]>flag:
+        maxIndex=mid-1
+    elif num_list[mid]<flag:
+        minIndex=mid+1
+    elif maxIndex<minIndex:
+        print("NO!FOUND!!!")
+        break
+
+
+