auto save

1.py

+num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
+N = len(num_list)
+L = 0
+H = N - 1
+num = 20
+while True:
+    print(L,H)
+    M = (L + H) // 2
+   
+    G = num_list[M]
+    if G == num:
+        print('找到了,在第' ,M+1 , '个')
+        break
+    elif H < L:
+        print('没找到')
+        break
+    elif num < G:
+        H = M - 1
+    else:
+        L = M + 1
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2.py

+num_list = []
+def search(num_list,num):
+    low=0
+    high=len(num_list)-1
+    
+    while True:
+        mid=(low+high) // 2
+        if num_list[mid] == num:
+            return "找到了。在"+str(mid+1)+"个。"   
+        elif low > high:
+            return "没找到。" 
+        elif num_list[mid] < num:
+            low=mid+1
+        else:
+            high=mid-1
+for i in range(1,101):
+    num_list.append(i)
+print(search(num_list,99))
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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]
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+#求长度，方便最高索引
+#求最低索引和最高索引，以及要查找的数据
+n = len(num_list)
+low = 0
+high = n-1 #high = len(num_list) - 1
+num = 20
+while True:
+    #中间索引 = (最低索引+最高索引) // 2
+    print(low,high)
+    mid = (low+high) // 2
+    if num == num_list[mid]:
+        print("找到了,在第",mid+1,'个')
+        break
+    elif low > high:
+        print("没找到")
+        break
+    elif num > num_list[mid]:
+        low = mid + 1
+    else:
+        high = mid - 1
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