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]
+high = len(num_list)
+low = 0
+num = 20
+while low <= high:
+    mid = (high + low)//2
+    guess = num_list[mid]
+    if guess > num:
+        high = mid - 1
+    elif guess == num:
+        print("找到了")
+        break
+    else:
+        low = mid + 1
+if low > high:
+    print("没找到")

my_search.py

@@ -6,4 +6,19 @@ for i in range(1, 101):
 num = random.choice(alist)
 # 请完善二分查找函数binary_search(),查找出num在列表alist里面的索引位置
 
-def binary_search(alist,num):
\ No newline at end of file
+def binary_search(alist,num):
+    low = 0
+    high = len(alist)-1
+    print(num)
+    while low <= high:
+        mid = (high + low)//2
+        guess = alist[mid]
+        if guess > num:
+            high = mid - 1
+        elif guess == num:
+            print("找到了",mid)
+            return
+        else:
+            low = mid + 1
+binary_search(alist,num)
+    
\ No newline at end of file