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]
+# mid = 0
+# low = 0
+# num = 0
+# high = len(num_list) - 1
+# guess = 0
+
+# mid = (low+high)//2
+# guess = num_list[mid]
+# if guess == num :
+#     print(mid)
+# if guess < num:
+#     low = mid + 1
+# else:
+#     high = mid - 1
+
+guess = int(input("请输入你要找的数:"))
+low = 0
+high = len(num_list)
+while high >= low:
+    mid = (low+high) // 2
+    if guess == num_list[mid]:
+        print(mid)
+        break
+    elif guess > num_list[mid]:
+        low = mid + 1
+    elif guess < num_list[mid]:
+        high = mid - 1
+if high < low:
+    print("你好，您输入的数值好像不存在呢")
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