| # | Problem | Pass Rate (passed user / total user) |
|---|---|---|
| 9272 | Max-Heap |
|
| 9328 | Queueing(I) |
|
| 9416 | Lexicographic Order |
|
Description
Please maintain a max-heap, which stores integers and is able to support following operations:
(1) PUSH k – Insert an integer k into the heap. k will fit in a 32-bit signed integer.
(2) POP – Delete the maximum element from the heap.
(3) TOP – Print the maximum element in the heap.
Input
There is only one set of commands. Each command occupies a line, and the total number of commands is less than or equal to 500000. You may assume that the number of elements stored in the heap will be no more than 10000 at any time.
Output
For each “TOP” command, output a line containing the value of the element on the top of the heap. In case that the heap is empty, print ”Null” instead.
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Description
You need to write a program to simulate a queue of names. Each name is a string consisting of English letters only. There are three operations:
1. “Push [name]”, which means to enque name in the queue.
2. “Pop”, which means to deque. If the queue is empty, this operation takes no effect.
3. “Front”, which means to print out the name in the front of queue. If the queue is empty, print "empty" (without quotes).
Input
There will be at most 107 operations. Each line contains one of the following operations. “Push [name]” (without quotes), “Pop” (without quotes), “Front”(without quotes). The length of each name is at most 20.
Case 1 : at most 103 operations
Case 2 : at most 105 operations
Case 3 : at most 107 operations
Case 4 : at most 107 operations
Output
For each “Front” operation, print out the name in the front of the queue.
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Description
There is a list of English words. Output them in lexicographic order. We compare the first character of two strings S1 and S2. If the ASCII code of the first character of S1 is smaller than the first character of S2, we said that S1 is smaller than S2. Otherwise, if their first characters are the same, we compare their second characters, so on so forth until we can determine their order. If S1 is S2’s prefix, S1 is smaller than S2 and vice versa.
Input
There are multiple test cases. Each case begins with an integer N in a line, and then N words follow, each word in a line. The maximum length of words is 50. The alphabets are 26 small English letters ‘a’ to ‘z’. The input is terminated if N = 0.
Case 1: 1 <= N <= 10
Case 2: 1 <= N <= 100
Case 3: 1 <= N <= 500
Case 4: 1 <= N <= 1000
Output
For each test case, print the words in lexicographic order. Print a blank line after each case.