Hi: I was solving this problem http://codeforces.me/problemset/problem/451/B

my idea in brief is to sort the input and repeatedly check if an entry has been moved(call it a[i]) in the sort ,where it is know and which entry it was exchanged with(call it a[j] )and check every entry between a[i] and a[j] to double sure that if it is a segment that was reversed , lastly check the number of the reversed segments to print the answer.

Here is the code:

 import java.util.*;
public class Main
{
	public static void main (String args[]){
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		int unsort[]=new int[n];
		int sort[]=new int[n];
		for(int i=0;i<unsort.length;i++){
			unsort[i]=sc.nextInt();
			sort[i]=unsort[i];
		}
      Arrays.sort(sort);
	  int co=0;int counter=0,id=0,id2=1;
	  for(int i=0;i<unsort.length;i++){
		  if(unsort[i]!=sort[i]){
			  co++;
			  int in=Arrays.binarySearch(sort,unsort[i]);
			  if(sort[i]==unsort[in]&&sort[i+1]==unsort[in-1]){
				  int i2=i;int in2=in;boolean b=false;
				  while(i2++<=in2--){
					  if(sort[i2]!=unsort[in2]){b=true;break;}
				  
				  }
				  if(b==false){
				  ++counter;id=i;id2=in;
				  i=in;}
			  }
		  }
	  }
	  ++id;++id2;
	  if(co==0){id=1;id2=1;}
	  System.out.println((counter==1||co==0)?"yes\n"+id+" "+id2:"no");
	}
	
}

Edit:changed the blog as you said :)