-// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// option. This file may not be copied, modified, or distributed
// except according to those terms.
+#![feature(phase)]
+#[phase(syntax)] extern crate green;
+extern crate sync;
+
+use sync::Arc;
+
+green_start!(main)
+
//
// Utilities.
//
-
// returns an infinite iterator of repeated applications of f to x,
// i.e. [x, f(x), f(f(x)), ...], as haskell iterate function.
fn iterate<'a, T>(x: T, f: |&T|: 'a -> T) -> Iterate<'a, T> {
// Takes a piece with minimum coordinate (0, 0) (as generated by
// transform). Returns the corresponding mask if p translated by (dy,
// dx) is on the board.
-fn mask(dy: int, dx: int, id: uint, p: &[(int, int)]) -> Option<u64> {
+fn mask(dy: int, dx: int, id: uint, p: &Vec<(int, int)>) -> Option<u64> {
let mut m = 1 << (50 + id);
for &(y, x) in p.iter() {
let x = x + dx + (y + (dy % 2)) / 2;
Some(m)
}
-// Makes every possible masks. masks[id][i] correspond to every
+// Makes every possible masks. masks[i][id] correspond to every
// possible masks for piece with identifier id with minimum coordinate
// (i/5, i%5).
fn make_masks() -> Vec<Vec<Vec<u64> > > {
vec!((0,0),(0,1),(0,2),(1,0),(1,2)),
vec!((0,0),(0,1),(0,2),(1,2),(1,3)),
vec!((0,0),(0,1),(0,2),(0,3),(1,2)));
- let mut res = Vec::new();
- for (id, p) in pieces.move_iter().enumerate() {
- // To break the central symetry of the problem, every
- // transformation must be taken except for one piece (piece 3
- // here).
- let trans = transform(p, id != 3);
- let mut cur_piece = Vec::new();
- for dy in range(0, 10) {
- for dx in range(0, 5) {
- let masks =
- trans.iter()
- .filter_map(|t| mask(dy, dx, id, t.as_slice()))
- .collect();
- cur_piece.push(masks);
- }
- }
- res.push(cur_piece);
- }
- res
+
+ // To break the central symetry of the problem, every
+ // transformation must be taken except for one piece (piece 3
+ // here).
+ let transforms: Vec<Vec<Vec<(int, int)>>> =
+ pieces.move_iter().enumerate()
+ .map(|(id, p)| transform(p, id != 3))
+ .collect();
+
+ range(0, 50).map(|yx| {
+ transforms.iter().enumerate().map(|(id, t)| {
+ t.iter().filter_map(|p| mask(yx / 5, yx % 5, id, p)).collect()
+ }).collect()
+ }).collect()
}
// Check if all coordinates can be covered by an unused piece and that
// all unused piece can be placed on the board.
-fn is_board_unfeasible(board: u64, masks: &[Vec<Vec<u64> > ]) -> bool {
+fn is_board_unfeasible(board: u64, masks: &Vec<Vec<Vec<u64>>>) -> bool {
let mut coverable = board;
- for i in range(0, 50).filter(|&i| board & 1 << i == 0) {
- for (cur_id, pos_masks) in masks.iter().enumerate() {
- if board & 1 << (50 + cur_id) != 0 {continue;}
- for &cur_m in pos_masks.get(i as uint).iter() {
- if cur_m & board == 0 {coverable |= cur_m;}
+ for (i, masks_at) in masks.iter().enumerate() {
+ if board & 1 << i != 0 { continue; }
+ for (cur_id, pos_masks) in masks_at.iter().enumerate() {
+ if board & 1 << (50 + cur_id) != 0 { continue; }
+ for &cur_m in pos_masks.iter() {
+ if cur_m & board != 0 { continue; }
+ coverable |= cur_m;
+ // if every coordinates can be covered and every
+ // piece can be used.
+ if coverable == (1 << 60) - 1 { return false; }
}
}
- if coverable & (1 << i) == 0 {return true;}
+ if coverable & 1 << i == 0 { return true; }
}
- // check if every coordinates can be covered and every piece can
- // be used.
- coverable != (1 << 60) - 1
+ true
}
// Filter the masks that we can prove to result to unfeasible board.
-fn filter_masks(masks: &[Vec<Vec<u64> > ]) -> Vec<Vec<Vec<u64> > > {
- masks.iter().map(
- |p| p.iter().map(
- |p| p.iter()
- .map(|&m| m)
+fn filter_masks(masks: &mut Vec<Vec<Vec<u64>>>) {
+ for i in range(0, masks.len()) {
+ for j in range(0, masks.get(i).len()) {
+ *masks.get_mut(i).get_mut(j) =
+ masks.get(i).get(j).iter().map(|&m| m)
.filter(|&m| !is_board_unfeasible(m, masks))
- .collect())
- .collect())
- .collect()
+ .collect();
+ }
+ }
}
// Gets the identifier of a mask.
fn get_id(m: u64) -> u8 {
- for id in range(0, 10) {
- if m & (1 << (id + 50)) != 0 {return id as u8;}
+ for id in range(0u8, 10) {
+ if m & (1 << (id + 50)) != 0 {return id;}
}
fail!("{:016x} does not have a valid identifier", m);
}
// Converts a list of mask to a ~str.
-fn to_utf8(raw_sol: &List<u64>) -> ~str {
- let mut sol: Vec<u8> = Vec::from_elem(50, '.' as u8);
+fn to_vec(raw_sol: &List<u64>) -> Vec<u8> {
+ let mut sol = Vec::from_elem(50, '.' as u8);
for &m in raw_sol.iter() {
- let id = get_id(m);
- for i in range(0, 50) {
+ let id = '0' as u8 + get_id(m);
+ for i in range(0u, 50) {
if m & 1 << i != 0 {
- *sol.get_mut(i as uint) = '0' as u8 + id;
+ *sol.get_mut(i) = id;
}
}
}
- std::str::from_utf8(sol.as_slice()).unwrap().to_owned()
+ sol
}
// Prints a solution in ~str form.
-fn print_sol(sol: &str) {
- for (i, c) in sol.chars().enumerate() {
+fn print_sol(sol: &Vec<u8>) {
+ for (i, c) in sol.iter().enumerate() {
if (i) % 5 == 0 { println!(""); }
if (i + 5) % 10 == 0 { print!(" "); }
- print!("{} ", c);
+ print!("{} ", *c as char);
}
println!("");
}
// The data managed during the search
struct Data {
- // If more than stop_after is found, stop the search.
- stop_after: int,
// Number of solution found.
nb: int,
// Lexicographically minimal solution found.
- min: ~str,
+ min: Vec<u8>,
// Lexicographically maximal solution found.
- max: ~str
+ max: Vec<u8>
+}
+impl Data {
+ fn new() -> Data {
+ Data {nb: 0, min: vec!(), max: vec!()}
+ }
+ fn reduce_from(&mut self, other: Data) {
+ self.nb += other.nb;
+ let Data { min: min, max: max, ..} = other;
+ if min < self.min { self.min = min; }
+ if max > self.max { self.max = max; }
+ }
}
// Records a new found solution. Returns false if the search must be
// stopped.
-fn handle_sol(raw_sol: &List<u64>, data: &mut Data) -> bool {
+fn handle_sol(raw_sol: &List<u64>, data: &mut Data) {
// because we break the symetry, 2 solutions correspond to a call
// to this method: the normal solution, and the same solution in
// reverse order, i.e. the board rotated by half a turn.
data.nb += 2;
- let sol1 = to_utf8(raw_sol);
- let sol2: ~str = sol1.chars().rev().collect();
+ let sol1 = to_vec(raw_sol);
+ let sol2: Vec<u8> = sol1.iter().rev().map(|x| *x).collect();
if data.nb == 2 {
data.min = sol1.clone();
data.max = sol1.clone();
}
- if sol1 < data.min {data.min = sol1.clone();}
- if sol2 < data.min {data.min = sol2.clone();}
- if sol1 > data.max {data.max = sol1;}
- if sol2 > data.max {data.max = sol2;}
- data.nb < data.stop_after
+ if sol1 < data.min {data.min = sol1;}
+ else if sol1 > data.max {data.max = sol1;}
+ if sol2 < data.min {data.min = sol2;}
+ else if sol2 > data.max {data.max = sol2;}
}
-// Search for every solutions. Returns false if the search was
-// stopped before the end.
fn search(
- masks: &[Vec<Vec<u64> > ],
+ masks: &Vec<Vec<Vec<u64>>>,
board: u64,
- mut i: int,
+ mut i: uint,
cur: List<u64>,
data: &mut Data)
- -> bool
{
// Search for the lesser empty coordinate.
while board & (1 << i) != 0 && i < 50 {i += 1;}
// the board is full: a solution is found.
if i >= 50 {return handle_sol(&cur, data);}
+ let masks_at = masks.get(i);
// for every unused piece
- for id in range(0, 10).filter(|id| board & (1 << (id + 50)) == 0) {
+ for id in range(0u, 10).filter(|id| board & (1 << (id + 50)) == 0) {
// for each mask that fits on the board
- for &m in masks[id as uint].get(i as uint)
- .iter()
- .filter(|&m| board & *m == 0) {
+ for &m in masks_at.get(id).iter().filter(|&m| board & *m == 0) {
// This check is too costy.
//if is_board_unfeasible(board | m, masks) {continue;}
- if !search(masks, board | m, i + 1, Cons(m, &cur), data) {
- return false;
- }
+ search(masks, board | m, i + 1, Cons(m, &cur), data);
}
}
- return true;
+}
+
+fn par_search(masks: Vec<Vec<Vec<u64>>>) -> Data {
+ let masks = Arc::new(masks);
+ let (tx, rx) = channel();
+
+ // launching the search in parallel on every masks at minimum
+ // coordinate (0,0)
+ for &m in masks.get(0).iter().flat_map(|masks_pos| masks_pos.iter()) {
+ let masks = masks.clone();
+ let tx = tx.clone();
+ spawn(proc() {
+ let mut data = Data::new();
+ search(&*masks, m, 1, Cons(m, &Nil), &mut data);
+ tx.send(data);
+ });
+ }
+
+ // collecting the results
+ drop(tx);
+ let mut data = rx.recv();
+ for d in rx.iter() { data.reduce_from(d); }
+ data
}
fn main () {
- let args = std::os::args();
- let args = args.as_slice();
- let stop_after = if args.len() <= 1 {
- 2098
- } else {
- from_str(args[1]).unwrap()
- };
- let masks = make_masks();
- let masks = filter_masks(masks.as_slice());
- let mut data = Data {stop_after: stop_after, nb: 0, min: "".to_owned(), max: "".to_owned()};
- search(masks.as_slice(), 0, 0, Nil, &mut data);
+ let mut masks = make_masks();
+ filter_masks(&mut masks);
+ let data = par_search(masks);
println!("{} solutions found", data.nb);
- print_sol(data.min);
- print_sol(data.max);
+ print_sol(&data.min);
+ print_sol(&data.max);
println!("");
}
projects / rust.git / commitdiff