MKJUMPS  Making Jumps
A knight is a piece used in the game of chess. The chessboard itself is square array of cells. Each time a knight moves, its resulting position is two rows and one column, or two columns and one row away from its starting position. Thus a knight starting on row r, column c – which we’ll denote as (r,c) – can move to any of the squares (r2,c1), (r2,c+1), (r1,c2), (r1,c+2), (r+1,c2), (r+1,c+2), (r+2,c1), or (r+2,c+1). Of course, the knight may not move to any square that is not on the board.
Suppose the chessboard is not square, but instead has rows with variable numbers of columns, and with each row offset zero or more columns to the right of the row above it. The figure to the left illustrates one possible configuration. How many of the squares in such a modified chessboard can a knight, starting in the upper left square (marked with an asterisk), not reach in any number of moves without resting in any square more than once?
If necessary, the knight is permitted to pass over regions that are outside the borders of the modified chessboard, but as usual, it can only move to squares that are within the borders of the board.
Input
There will be multiple cases to consider. The input for each case begins with an integer n, between 1 and 10, that specifies the number of rows in the modified chessboard. Following n there will be n pairs of integers, with the ith pair corresponding to the ith row of the chessboard. The first integer of each pair indicates the number of squares skipped at the beginning of the row. The second integer indicates the number of squares in the row (which will always be at least 1).The last case will be followed by the integer 0.
For example, input for the case illustrated by the chessboard shown above would be:
7 0 3 0 3 0 4 0 4 1 3 1 7 4 4
The maximum dimensions of the board will be 10 rows and 10 columns. That is, any modified chessboard specified by the input will fit completely on a 10 row, 10 column board.
Output
For each input case, display the case number (1, 2, …), and the number of squares that the knight can not reach. Display the results in the format shown in the examples below.
Example
Input: 7 0 3 0 3 0 4 0 4 1 3 1 7 4 4 3 0 3 0 3 0 3 2 0 1 2 1 0 Output: Case 1, 4 squares can not be reached. Case 2, 1 square can not be reached. Case 3, 0 squares can not be reached.
hide comments
scoobybutter:
20160426 18:28:56
my 100th :) 

spoj2121:
20160424 20:23:08
1 square and 4 squares...check it..cost me 1WA 

Arjav Patel:
20151229 06:51:52
DFS and Backtracking! 

Oasis:
20151022 14:26:14
5 WA just because i forgot space between can and not..... 

MAYANK NARULA:
20151017 12:34:06
easy concept .. a bit more tough implementation on my first BACKTRACK !!!


Avi Aryan:
20150715 14:49:24
Initially the author says "and with each row offset zero or more columns to the right of the row above it."


: : still coding _ ::
20150516 13:53:24
I dont understand the knight can cover the entire chess board...how can the answer for first testcase be 4..HELP.!! 

AAKASH TYAGI:
20141203 14:09:25
print "square" instead of "squares" if your answer is 1. I got one wa bcz of that 

do_do:
20141014 20:22:48
finally green light :).. try to move in consecutive moves and than explore the max box you can visit .. .. thanks @amaroq and mohannad abdullah hassan


rishabh aggarwal:
20141005 22:29:44
thnx a lot amaroz.

Added by:  Camilo Andrés Varela León 
Date:  20070511 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ERL JSRHINO NODEJS PERL6 VB.NET 
Resource:  North Central North America Regional Programming Contest  2003 