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Spirals (Posted on 2003-08-21) Difficulty: 3 of 5
Write a program (or explain how to do it) that will display a descending "spiral" of NxN numbers, using constant space (no arrays allowed). For example, here's what the spiral looks like for N=10:
   99    98    97    96    95    94    93    92    91    90
   64    63    62    61    60    59    58    57    56    89
   65    36    35    34    33    32    31    30    55    88
   66    37    16    15    14    13    12    29    54    87
   67    38    17     4     3     2    11    28    53    86
   68    39    18     5     0     1    10    27    52    85
   69    40    19     6     7     8     9    26    51    84
   70    41    20    21    22    23    24    25    50    83
   71    42    43    44    45    46    47    48    49    82
   72    73    74    75    76    77    78    79    80    81

See The Solution Submitted by DJ    
Rating: 4.4167 (12 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
re(3): solution | Comment 7 of 11 |
(In reply to re(2): solution by Charlie)

You are absolutely correct in what my program does! It DOES go the opposite way for odd N....

This is because the problem specified a "descending spiral"....


I interpret this to mean the upper left corner has the HIGHEST valued number. My program is consistent with this notion. It is left as an exercise to the reader (easy enough) to change my code to always have the '1' to the right of the '0'.
  Posted by Your buddy on 2003-08-21 17:28:26

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