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]
\ No newline at end of file
+num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
+b_n =20      #要找的
+low = 0              #最低值
+high = len(num_list)-1#最高
+while low <=high:  #条件循环
+    mid = (low+high)//2  #中间
+    g_n = num_list[mid]  #中间索引的数
+    if g_n == b_n:  #中间的数=对
+        print('找到了，索引是：',mid) #提示
+        break
+    elif g_n < b_n:  #猜<对
+        low = mid+1  #最低
+    elif g_n > b_n:   #猜>对
+        high = mid-1 #最高
+
+