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]
+low = 0
+high = len(num_list) - 1
+n=0
+while True:
+    n = n+1
+    mid = (low+high) // 2
+    if num_list[mid] == 20:
+        print("找到了,用了"+str(n) + "次")
+        break
+    elif num_list[mid] < 20:
+        low = mid + 1
+    else:
+        high = mid - 1
+    if high <low:
+        print("没找到,用了"+str(n)+"次")
+        break