Swapping Method
The swapping method for solution of Survo puzzles has been created by combining the idea of the original solver program to the observation that the products of the marginal sums crudely indicate the positions of the correct numbers in the final solution. The procedure is started by filling the original table by numbers 1,2,...,m·n according to sizes of these products and by computing row and column sums according to this initial setup. Depending on how these sums deviate from the true sums, it is tried to improve the solution by swapping two numbers at a time. When using the swapping method the nature of solving Survo puzzles becomes somewhat similar to that of Chess problems. By this method it is hardly possible to verify the uniqueness of the solution.
For example, a rather demanding 4 × 4 puzzle (MD=2050)
| 51 | ||||
| 36 | ||||
| 32 | ||||
| 17 | ||||
| 51 | 42 | 26 | 17 |
is solved by 5 swaps. The initial setup is
| Sum | OK | error | |||||
| 16 | 15 | 10 | 8 | 49 | 51 | -2 | |
| 14 | 12 | 9 | 4 | 39 | 36 | 3 | |
| 13 | 11 | 6 | 3 | 33 | 32 | 1 | |
| 7 | 5 | 2 | 1 | 15 | 17 | -2 | |
| Sum | 50 | 43 | 27 | 16 | |||
| OK | 51 | 42 | 26 | 17 | |||
| error | -1 | 1 | 1 | -1 |
and the solution is found by swaps (7,9) (10,12) (10,11) (15,16) (1,2). In the Survo system, a sucro /SP_SWAP takes care of bookkeeping needed in the swapping method.
Read more about this topic: Survo Puzzle
Famous quotes containing the words swapping and/or method:
“sailing
In sunlight smiling under their goggles swapping batons back and
forth
And He who jumped without a chute and was handed one by a diving
Buddy.”
—James Dickey (b. 1923)
“A method of child-rearing is not—or should not be—a whim, a fashion or a shibboleth. It should derive from an understanding of the developing child, of his physical and mental equipment at any given stage, and, therefore, his readiness at any given stage to adapt, to learn, to regulate his behavior according to parental expectations.”
—Selma H. Fraiberg (20th century)