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
-bingo_num=20
-while low<=high:
-    mid=(low+high)//2
-    guess_num=num_list[mid]
-    if guess_num==bingo_num:
-        print(mid)
-        break
-    elif guess_num<bingo_num:
-        low=mid+1
-    else:
-        high=mid-1
-print(mid)
+def binary_search(alist,num):
+    low=0
+    high=len(num_list)-1
+    while low<=high:
+        mid=(low+high)//2
+        guess_num=alist[mid]
+        if guess_num==num:
+            print(mid)
+            break
+        elif guess_num<num:
+            low=mid+1
+        else:
+            high=mid-1
+    return None
+result=binary_search(num_list,17)