ShoutterDiv2

/*
Problem Statement for ShoutterDiv2


Problem Statement
    	
A group of freshman rabbits has recently joined the Eel club. No two of the rabbits knew each other. Today, each of the rabbits went to the club for the first time. You are given int[]s s and t with the following meaning: For each i, rabbit number i entered the club at the time s[i] and left the club at the time t[i].

Each pair of rabbits that was in the club at the same time got to know each other, and they became friends on the social network service Shoutter. This is also the case for rabbits who just met for a single moment (i.e., one of them entered the club exactly at the time when the other one was leaving).

Compute and return the number of pairs of rabbits that became friends today.

 
Definition
    	
Class:	ShoutterDiv2
Method:	count
Parameters:	int[], int[]
Returns:	int
Method signature:	int count(int[] s, int[] t)
(be sure your method is public)
    
 
Constraints
-	s and t will contain between 1 and 50 integers, inclusive.
-	s and t will contain the same number of elements.
-	Each integer in s and t will be between 0 and 100, inclusive.
-	For each i, t[i] will be greater than or equal to s[i].
 
Examples
0)	
    	
{1, 2, 4}
{3, 4, 6}
Returns: 2
Rabbit 0 and Rabbit 1 will be friends because both of them are in the club between time 2 and 3. 

Rabbit 0 and Rabbit 2 won't be friends because Rabbit 0 will leave the club before Rabbit 2 enters the club. 

Rabbit 1 and Rabbit 2 will be friends because both of them are in the club at time 4. 

1)	
    	
{0}
{100}
Returns: 0
2)	
    	
{0,0,0}
{1,1,1}
Returns: 3
3)	
    	
{9,26,8,35,3,58,91,24,10,26,22,18,15,12,15,27,15,60,76,19,12,16,37,35,25,4,22,47,65,3,2,23,26,33,7,11,34,74,67,32,15,45,20,53,60,25,74,13,44,51}
{26,62,80,80,52,83,100,71,20,73,23,32,80,37,34,55,51,86,97,89,17,81,74,94,79,85,77,97,87,8,70,46,58,70,97,35,80,76,82,80,19,56,65,62,80,49,79,28,75,78}
Returns: 830
*/

public class ShouttleDiv2 {
	public static void main(String argv[]){
		int s[]={9,26,8,35,3,58,91,24,10,26,22,18,15,12,15,27,15,60,76,19,12,16,37,35,25,4,22,47,65,3,2,23,26,33,7,11,34,74,67,32,15,45,20,53,60,25,74,13,44,51};
		
		int t[]={26,62,80,80,52,83,100,71,20,73,23,32,80,37,34,55,51,86,97,89,17,81,74,94,79,85,77,97,87,8,70,46,58,70,97,35,80,76,82,80,19,56,65,62,80,49,79,28,75,78};
		
		System.out.println(new ShouttleDiv2().count(s,t));
	}
	
	public int count(int []s,int []t){
		int counter=0;
		if(s.length<=0 || s.length !=t.length)
		{
			throw new IllegalArgumentException("");
			//return counter;
		}
		for(int i=0;i<s.length;i++)
		{
			for(int j=i+1;j<s.length;j++)
			{
				if(s[i]>t[j] || s[j]>t[i])continue;
					counter ++;
			}
		}
		
		return counter;
	}
}

算法复杂度，穷举O(N^2)