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]
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+
+def search(num):
+    num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
+    length=len(num_list)
+    low=0;high=length-1;mid=(low+high)//2
+    while(1):
+        if num == num_list[mid]:
+            print(mid,"\n")
+            break;
+        elif low>high:
+            print("none\n")
+            break;
+        if num_list[mid] < num:
+            low=mid+1;
+        else:
+            high=mid-1;
+        mid=(low+high)//2
+
+search(9)
+search(20)
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