var max_solutions = flag.Int("n", 2100, "maximum number of solutions")
-
func boolInt(b bool) int8 {
if b {
return 1
[4]int8{E, E, E, SW},
}
-
/* To minimize the amount of work done in the recursive solve function below,
* I'm going to allocate enough space for all legal rotations of each piece
* at each position on the board. That's 10 pieces x 50 board positions x
/* Returns the direction flipped on the horizontal axis */
func flip(dir int8) int8 { return (PIVOT - dir) % PIVOT }
-
/* Returns the new cell index from the specified cell in the
* specified direction. The index is only valid if the
* starting cell and direction have been checked by the
piece_counts[piece][minimum]++
}
-
/* Fill the entire board going cell by cell. If any cells are "trapped"
* they will be left alone.
*/
}
}
-
/* To thin the number of pieces, I calculate if any of them trap any empty
* cells at the edges. There are only a handful of exceptions where the
* the board can be solved with the trapped cells. For example: piece 8 can
return true
}
-
/* Calculate all six rotations of the specified piece at the specified index.
* We calculate only half of piece 3's rotations. This is because any solution
* found has an identical solution rotated 180 degrees. Thus we can reduce the
}
}
-
/* Calculate all 32 possible states for a 5-bit row and all rows that will
* create islands that follow any of the 32 possible rows. These pre-
* calculated 5-bit rows will be used to find islands in a partially solved
}
}
-
/* Calculate islands while solving the board.
*/
func boardHasIslands(cell int8) int8 {
return bad_even_triple[current_triple]
}
-
/* The recursive solve algorithm. Try to place each permutation in the upper-
* leftmost empty cell. Mark off available pieces as it goes along.
* Because the board is a bit mask, the piece number and bit mask must be saved
var (
jupiter = Body{
- x: 4.84143144246472090e+00,
- y: -1.16032004402742839e+00,
- z: -1.03622044471123109e-01,
- vx: 1.66007664274403694e-03 * daysPerYear,
- vy: 7.69901118419740425e-03 * daysPerYear,
- vz: -6.90460016972063023e-05 * daysPerYear,
+ x: 4.84143144246472090e+00,
+ y: -1.16032004402742839e+00,
+ z: -1.03622044471123109e-01,
+ vx: 1.66007664274403694e-03 * daysPerYear,
+ vy: 7.69901118419740425e-03 * daysPerYear,
+ vz: -6.90460016972063023e-05 * daysPerYear,
mass: 9.54791938424326609e-04 * solarMass,
}
saturn = Body{
- x: 8.34336671824457987e+00,
- y: 4.12479856412430479e+00,
- z: -4.03523417114321381e-01,
- vx: -2.76742510726862411e-03 * daysPerYear,
- vy: 4.99852801234917238e-03 * daysPerYear,
- vz: 2.30417297573763929e-05 * daysPerYear,
+ x: 8.34336671824457987e+00,
+ y: 4.12479856412430479e+00,
+ z: -4.03523417114321381e-01,
+ vx: -2.76742510726862411e-03 * daysPerYear,
+ vy: 4.99852801234917238e-03 * daysPerYear,
+ vz: 2.30417297573763929e-05 * daysPerYear,
mass: 2.85885980666130812e-04 * solarMass,
}
uranus = Body{
- x: 1.28943695621391310e+01,
- y: -1.51111514016986312e+01,
- z: -2.23307578892655734e-01,
- vx: 2.96460137564761618e-03 * daysPerYear,
- vy: 2.37847173959480950e-03 * daysPerYear,
- vz: -2.96589568540237556e-05 * daysPerYear,
+ x: 1.28943695621391310e+01,
+ y: -1.51111514016986312e+01,
+ z: -2.23307578892655734e-01,
+ vx: 2.96460137564761618e-03 * daysPerYear,
+ vy: 2.37847173959480950e-03 * daysPerYear,
+ vz: -2.96589568540237556e-05 * daysPerYear,
mass: 4.36624404335156298e-05 * solarMass,
}
neptune = Body{
- x: 1.53796971148509165e+01,
- y: -2.59193146099879641e+01,
- z: 1.79258772950371181e-01,
- vx: 2.68067772490389322e-03 * daysPerYear,
- vy: 1.62824170038242295e-03 * daysPerYear,
- vz: -9.51592254519715870e-05 * daysPerYear,
+ x: 1.53796971148509165e+01,
+ y: -2.59193146099879641e+01,
+ z: 1.79258772950371181e-01,
+ vx: 2.68067772490389322e-03 * daysPerYear,
+ vy: 1.62824170038242295e-03 * daysPerYear,
+ vz: -9.51592254519715870e-05 * daysPerYear,
mass: 5.15138902046611451e-05 * solarMass,
}
sun = Body{