#6 Div2 E. Exposition（RMQ+最长连续子序列变形）

小灰灰 2022-07-03 19:52 34阅读 0赞

[点击打开链接][Link 1]

http://codeforces.com/contest/6/problem/E

E. Exposition

There are several days left before the fiftieth birthday of a famous Berland's writer Berlbury. In this connection the local library decided to make an exposition of the works of this famous science-fiction writer. It was decided as well that it is necessary to include into the exposition only those books that were published during a particular time period. It is obvious that if the books differ much in size, the visitors will not like it. That was why the organizers came to the opinion, that the difference between the highest and the lowest books in the exposition should be not more than *k*millimeters.

The library has *n* volumes of books by Berlbury, arranged in chronological order of their appearance. The height of each book in millimeters is know, it is *h**i*. As Berlbury is highly respected in the city, the organizers want to include into the exposition as many books as possible, and to find out what periods of his creative work they will manage to cover. You are asked to help the organizers cope with this hard task.

Input

The first line of the input data contains two integer numbers separated by a space *n* (1 ≤ *n* ≤ 105) and *k* (0 ≤ *k* ≤ 106) — the amount of books by Berlbury in the library, and the maximum allowed height difference between the lowest and the highest books. The second line contains *n* integer numbers separated by a space. Each number *h**i* (1 ≤ *h**i* ≤ 106) is the height of the *i*\-th book in millimeters.

Output

In the first line of the output data print two numbers *a* and *b* (separate them by a space), where *a* is the maximum amount of books the organizers can include into the exposition, and *b* — the amount of the time periods, during which Berlbury published *a* books, and the height difference between the lowest and the highest among these books is not more than *k* milllimeters.

In each of the following *b* lines print two integer numbers separated by a space — indexes of the first and the last volumes from each of the required time periods of Berlbury's creative work.

Examples

input

3 3
    14 12 10

output

2 2
    1 2
    2 3

input

2 0
    10 10

output

2 1
    1 2

input

4 5
    8 19 10 13

output

2 1
    3 4

题意：额，就是让你求最长连续子序列，规定这个序列中的最大值和最小值相差不能超过K。

问你最长是多少。有多少个最长？并要求把它们的区间下标输出。

题解：用multiset保存这些数前缀，然后一个区间一个区间得check，不适合的小范围对于大范围也肯定不适合，可以把这个数删了，然后不断进行RMQ就可以了。

AC代码：

#include<bits/stdc++.h>
    using namespace std;
    int a[100010];
    int n,k;
    vector<pair<int,int>>vp;
    multiset<int>s; 
    int main()
    {
    	cin>>n>>k;
    	for(int i=0;i<n;i++)cin>>a[i];
    	int j=0;
    	int ans = -1;
    	for(int i=0;i<n;i++)
    	{
    		s.insert(a[i]);
    		while(*s.rbegin()-*s.begin()>k) s.erase(s.find(a[j++]));
    		if(i-j+1>ans)
    		{
    			ans=i-j+1;
    			vp.clear(); //要求vp坐标是最大的，注意将前面的清空 
    		}
    		if(i-j+1==ans)//记录新的最大和之后同等最大的坐标 
    		{
    			vp.push_back(make_pair(j+1,i+1));
    		}
    	}
    	cout<<ans<<" "<<vp.size()<<endl;
    	for(int i=0;i<vp.size();i++)
    	{
    		cout<<vp[i].first<<" "<<vp[i].second<<endl;
    	}
    	return 0;
     }

[Link 1]: http://codeforces.com/contest/6/problem/E