Problem Statement 
 A group of people have participated in an online chat session. Element i (0based) of numSeen contains the number of lines of chat seen by person i before leaving (everyone arrives at the same time). More precisely, integer j in element i of numSeen is the exact number of lines written by person j that are seen by person i before leaving. Integer i of element i will always be 0, and should be ignored. You will return a int[] containing the order in which each person left. If multiple orders are possible, return the one that occurs first lexicographically. If none are possible, return an empty int[]. 

Definition 
 Class:  ChatExit  Method:  leaveOrder  Parameters:  String[]  Returns:  int[]  Method signature:  int[] leaveOrder(String[] numSeen)  (be sure your method is public) 




Notes 
  Order A comes lexicographically before order B if A has a lower value than B in the first position that they disagree. 

Constraints 
  numSeen will contain between 2 and 25 elements inclusive. 
  Each element of numSeen will contain between 3 and 50 characters inclusive. 
  Each element of numSeen will be a single space delimited list of integers. Each integer will be between 0 and 100 inclusive, and will have no extra leading zeros. 
  Each element of numSeen will contain exactly k integers, where k is the number of elements in numSeen. 
  Integer i in element i of numSeen will always be 0. 

Examples 
0)  
 {
"0 1 1",
"2 0 0",
"3 1 0"
} 
 Returns: {1, 0, 2 }  A possible sequence of events is:
Person 0 writes a line.
Person 1 writes a line.
Person 0 writes a line.
Person 1 leaves.
Person 2 writes a line.
Person 0 writes a line.
Person 0 leaves.
Person 2 leaves.



1)  
 {
"0 1 1",
"4 0 0",
"3 1 0"
} 
 Returns: { }  No order is possible here due to the following requirements:
 Person 1 must see 4 lines from person 0, but person 2 must only see 3 lines from person 0.
 Person 0 must see 1 line from person 2, but person 1 must not see any.
The first item above forces person 1 to leave after person 2. The second item forces person 1 to leave before person 2. 


2)  
 {
"0 100 100 100 100 100",
"100 0 100 100 100 100",
"100 100 0 100 100 100",
"100 100 100 0 100 100",
"100 100 100 100 0 100",
"100 100 100 100 100 0"
} 
 Returns: {0, 1, 2, 3, 4, 5 }  Everyone says exactly 100 lines. Any leaving order is possible. The lexicographically first order is returned. 


3)  
 {
"0 1 0 0",
"1 0 0 0",
"0 0 0 0",
"0 0 0 0"
} 
 Returns: {2, 3, 0, 1 }  

4)  
 {
"0 0 0 0 0",
"0 0 0 0 0",
"0 0 0 0 0",
"0 0 0 0 0",
"0 0 0 0 0"
} 
 Returns: {0, 1, 2, 3, 4 }  
