杭电 4006 亚洲区预赛大连赛区-优快云博客

本文介绍了一种使用STL解决XiaoMing与XiaoBao之间进行的数字游戏问题的方法。玩家XiaoMing可以选择写下数字或者询问当前第k大的数字，文章通过C++代码实现了一个算法来帮助XiaoBao及时给出答案。

这个题是stl的典型应用了，当时zyc学长大概在貌似40多分钟的时候就做出来了，今天看了一下，，还是有一定难度的，主要是有个点不太好想，一般方法都超时，可以一直保留k个元素，是这道题得难点所在。。。。题目：

Xiao Ming and Xiao Bao are playing a simple Numbers game. In a round Xiao Ming can choose to write down a number, or ask Xiao Bao what the kth great number is. Because the number written by Xiao Ming is too much, Xiao Bao is feeling giddy. Now, try to help Xiao Bao.

Input

There are several test cases. For each test case, the first line of input contains two positive integer n, k. Then n lines follow. If Xiao Ming choose to write down a number, there will be an " I" followed by a number that Xiao Ming will write down. If Xiao Ming choose to ask Xiao Bao, there will be a "Q", then you need to output the kth great number.

Output

The output consists of one integer representing the largest number of islands that all lie on one line.

Sample Input

8 3
I 1
I 2
I 3
Q
I 5
Q
I 4
Q

Sample Output

1
2
3

ac代码：

#include <iostream> #include <algorithm> #include <set> #include <cstdio> using namespace std; int main() { int n,k; while(scanf("%d%d",&n,&k)!=EOF) { multiset<int> aaa; multiset<int>::const_iterator b; multiset<int>::const_iterator c; char ch; int x; while(n--) { cin>>ch; if(ch=='I') { cin>>x;aaa.insert(x); if(aaa.size()>k) aaa.erase(aaa.begin()); } if(ch=='Q') { printf("%d\n",*aaa.begin()); } } } return 0; }