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 = 20
-low = 0
-high = len(num_list)-1
+import random
+alist = []
+for i in range(1,101):
+    alist.append(i)
+num = random.choice(alist)
 
 
-while high >= low:
-    mid = (low + high)//2 
+def binary_search(alist,num):
+    high = len(alist)-1
+    low = 0
+    while high >= low:
+        mid = (low + high)//2 
 
 
-    guess = num_list[mid]
-    if guess == num:
-        print("找到了")
-        print(mid)
-        break
-    elif guess < num:
-        low = mid+1
-    elif guess > num:
-        high = mid-1
-if high < low:
-    print("没有这个数")
-    
+        guess = alist[mid]
+        if guess == num:
+            print("找到了")
+            return mid
+
+        elif guess < num:
+            low = mid+1
+        elif guess > num:
+            high = mid-1
+    if high < low:
+        print("没有这个数")
+
\ No newline at end of file
+
+g = binary_search(alist,num)
+print(g)
\ No newline at end of file