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
+def binary_search(alist,num):
+    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:
+            return mid
+        elif guess_num < bingo_num:
+            low = mid +1
+        else: 
+            low = mid - 1
 
 
-while low <= high:
-    mid = (low + high)//2
-    guess_num = num_list[mid]
+result = binary_search(num_list,20)
+print(result)
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-    if guess_num == bingo_num:
-        print(mid)
-        break
-    elif guess_num < bingo_num:
-        low = mid +1
-    else: 
-        low = mid - 1
\ No newline at end of file