想在mydict={'key1':1}中添加一个元素 'key2':2应该：
A: mydict.append('key2':2)
B: mydict.insert(0,{'key2':2})
C: mydict['key2']=2
D: mydict.pop()
A: mydict.append('key2':2)
B: mydict.insert(0,{'key2':2})
C: mydict['key2']=2
D: mydict.pop()
C
举一反三
- 如果有H(key)=key mod 13，若：key1=12,key2=25，那么key1与key2是同义词。
- 下面的SQL哪些有可能经过两个阶段（只经过一次shuffle）就计算出结果：（ ） A: SELECT key1, key2, SUM(value1) FROM (SELECT key1, key2, COUNT(*) FROM dual GROUP BY key1, key2) t1 GROUP BY key2, key1; B: SELECT a.key1, a.key2 FROM table1 a JOIN table2 b ON a.key1 = b.key; C: SELECT *, ROW_NUMBER() OVER(PARTITION BY key ORDER BY value1, value 2) id1, ROW_NUMBER() OVER(PARTITION BY key ORDER BY value1) id2 FROM dual;
- D = {'苹果': 4, '梨': 5, '榴莲': 1} D2 = {'香蕉': 3, '柠檬': 3, '凤梨':2 , '苹果':3} for key in D: for key2 in D2: if key == key2: print(D[key]+D2[key2]) 以上代码运行结果为（ ）? A: 10 B: 5 C: 7 D: 21
- 对不同的关键字可能得到同一哈希地址，即key≠key2而H（key1）=H（key2）这种现象称冲突。（）. A: 对 B: 错
- Planning in advance is the key to 2) .
内容
- 0
Four keys to getting hired are begun in different ways stylistically. Key 1 starts with a ____.Key 2 starts with a ___. Key 3 starts with a ____. Key4 starts with a ____.
- 1
How many key comparisons are needed in searching for key value 38（） A: 1 B: 2 C: 3 D: 4
- 2
代码填空【使用递归实现二分查找】 int binarySearch(int a[], int key, int low, int high) { if (low > high) return -1; int mid; mid = (low + high) / 2; if (key == a[mid]) return mid; else if (key < a[mid]) return ________(1)__________; else return ________(2)______________; }
- 3
两个集合元素的关键字为key1和key2，给定散列函数H，如果key1≠key2但是H(key1)=H(key2)，则这种现象称为____。
- 4
1. 已知列表对象x=[‘11’,’2’,’3’],则表达式max(x,key=len)的值为: ( )说明：key参数，参照sort函数的用法。 A: '11' B: '2' C: '3' D: 2