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8 Commits

Author SHA1 Message Date
81f52b5e43
[release] sudk v0.1.1 2024-09-28 10:25:31 +02:00
fe1077c6c1
[code] refactor, clippy, rustfmt
- added clippy lints and fixed the resulting issues
- moved build_possible_values_db() into the new() call
- extracted the skip_db functionality into their own functions
2024-09-28 10:25:16 +02:00
46c96a22ba
[perf] updated flamegraph 2024-02-08 19:00:36 +01:00
ae4263320e
[code] remove some unneeded unsafe 2024-02-08 18:56:44 +01:00
1202ae89a5
[build] user decides how to build 2023-12-08 11:37:56 +01:00
e74e05fa95
clangd warnings 2023-12-08 11:36:22 +01:00
fc9fc1a048
(fix) unsafe array access in skipf and skipb
skipf was accessed at index 81 (len only 81)
skipb was accessed at index -1 (u64::MAX)

I still don't know, why the skipb case didn't crash.
2023-06-16 16:57:25 +02:00
e446d9b74f
rust version: backtracking simplified and other improvements
* backtracking: main loop simplified
* instead of the `fixed` Vec, we now use skip fields to calculate
  how many fields to skip in `next()` and `prev()`.
  This is faster because we get rid of the `if` statement
  thus no branching occurs.
2023-03-27 21:04:04 +02:00
8 changed files with 637 additions and 304 deletions

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@ -1,3 +0,0 @@
[build]
target = "x86_64-unknown-linux-musl"
rustflags = "-C target-cpu=native -C strip=symbols"

2
Cargo.lock generated
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@ -4,4 +4,4 @@ version = 3
[[package]] [[package]]
name = "sudk" name = "sudk"
version = "0.1.0" version = "0.1.1"

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@ -1,13 +1,19 @@
[package] [package]
name = "sudk" name = "sudk"
version = "0.1.0" version = "0.1.1"
authors = ["ddidderr <ddidderr@paul.network>"] authors = ["ddidderr <ddidderr@paul.network>"]
edition = "2021" edition = "2021"
[lints.clippy]
pedantic = { level = "warn", priority = -1 }
todo = "warn"
unwrap_used = "warn"
[dependencies] [dependencies]
[profile.release] [profile.release]
lto = true lto = true
debug = false debug = false
codegen-units = 1 strip = true
panic = "abort" panic = "abort"
codegen-units = 1

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@ -1,6 +1,6 @@
#!/bin/bash #!/bin/bash
set -e set -e
clang -Wall -Wextra -Weverything -Werror -O3 -march=native -flto -std=c17 -fstack-protector-all -s -o sudk_c "$1" clang -Weverything -Wno-unsafe-buffer-usage -Werror -O3 -march=native -flto -std=c17 -fstack-protector-all -s -o sudk_c "$1"
time ./sudk_c time ./sudk_c

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@ -5,7 +5,7 @@
#include <stdlib.h> #include <stdlib.h>
#include <sys/types.h> #include <sys/types.h>
static inline void Print_Clear() { printf("\x1b\x5b\x48\x1b\x5b\x32\x4a"); } static inline void Print_Clear(void) { printf("\x1b\x5b\x48\x1b\x5b\x32\x4a"); }
typedef struct Sudoku { typedef struct Sudoku {
uint8_t *field; uint8_t *field;
@ -258,7 +258,7 @@ static void Sudoku_Free(Sudoku *s) {
s = NULL; s = NULL;
} }
int main() { int main(void) {
Sudoku *s = Sudoku_New(3); Sudoku *s = Sudoku_New(3);
Sudoku_Print(s); Sudoku_Print(s);
Sudoku_SolveBacktracking(s); Sudoku_SolveBacktracking(s);

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3
rustfmt.toml Normal file
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@ -0,0 +1,3 @@
group_imports = "StdExternalCrate"
imports_granularity = "Crate"
imports_layout = "HorizontalVertical"

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@ -2,120 +2,113 @@ use std::time::Instant;
const BLOCK_SIZE: usize = 3; const BLOCK_SIZE: usize = 3;
const SIZE: usize = BLOCK_SIZE * BLOCK_SIZE; const SIZE: usize = BLOCK_SIZE * BLOCK_SIZE;
const NUM_FIELDS: usize = SIZE * SIZE;
fn print_gray() {
print!("\x1b\x5b\x31\x3b\x33\x30\x6d");
}
fn print_green() {
print!("\x1b\x5b\x31\x3b\x33\x32\x6d");
}
fn print_neutral() {
print!("\x1b\x5b\x31\x3b\x30\x6d");
}
fn print_clear() {
print!("\x1b\x5b\x48\x1b\x5b\x32\x4a");
}
struct SField { struct SField {
field: Vec<u8>, field: Vec<u8>,
fixed: Vec<bool>, skip_forward: Vec<u8>,
size: usize, skip_backward: Vec<u8>,
block_size: usize,
pos: usize, pos: usize,
pos_last_placed: usize,
num_fields: usize,
possible_values: Vec<Vec<u8>>, possible_values: Vec<Vec<u8>>,
} }
/// Some test fields:
///
/// EMPTY FIELD
/// let field = vec![0; SIZE * SIZE];
///
/// MANY SOLUTIONS
/// #[rustfmt::skip]
/// let field = vec![
/// 0,0,0,0,0,0,0,0,9,
/// 0,0,0,0,8,9,0,2,0,
/// 0,0,0,0,2,0,4,0,0,
/// 0,0,4,0,6,0,0,0,8,
/// 0,0,0,5,0,0,0,0,0,
/// 0,6,5,0,0,2,0,7,4,
/// 0,3,0,0,0,5,0,4,0,
/// 0,0,1,8,0,0,0,0,0,
/// 0,0,8,2,0,0,0,6,0,
/// ];
///
/// HARD
/// #[rustfmt::skip]
/// let field = vec![
/// 8,4,0,0,6,0,5,0,1,
/// 0,0,0,0,0,3,0,4,0,
/// 0,0,6,9,0,0,0,0,7,
/// 0,2,0,7,1,0,0,0,6,
/// 0,0,0,6,3,0,0,0,0,
/// 9,0,0,0,0,0,0,5,0,
/// 0,0,0,0,4,0,0,6,0,
/// 2,0,0,0,0,0,1,8,0,
/// 0,0,5,0,0,0,3,0,0,
/// ];
///
/// EASY
/// #[rustfmt::skip]
/// let field = vec![
/// 5,9,0,6,1,3,0,0,0,
/// 0,0,0,9,0,0,5,0,0,
/// 8,0,3,0,5,7,6,4,0,
/// 0,7,5,0,0,0,4,0,6,
/// 0,6,0,7,4,0,2,0,8,
/// 2,0,8,0,0,0,7,5,3,
/// 0,0,0,5,6,1,0,7,0,
/// 0,0,1,0,7,0,9,0,0,
/// 7,3,6,0,2,0,0,0,0,
/// ];
///
/// // BLOCK_SIZE 4 MANY SOLUTIONS (DOESN'T FINISH)
/// #[rustfmt::skip]
/// let field = vec![
/// 0,15,0,0,0,0,11,4,0,5,0,0,0,0,12,8,
/// 12,0,0,9,0,1,0,5,0,0,8,15,0,0,0,13,
/// 0,0,3,0,0,10,13,0,0,11,4,0,15,0,6,0,
/// 13,10,0,11,0,0,0,14,0,3,2,0,0,9,0,0,
/// 0,0,15,10,8,0,0,0,0,0,14,0,0,6,2,0,
/// 0,0,14,0,0,0,6,0,0,0,0,0,1,0,0,0,
/// 0,11,0,8,3,0,15,1,6,0,0,0,0,0,0,7,
/// 0,6,0,7,0,0,0,0,8,13,0,0,10,0,0,0,
/// 0,14,0,2,0,0,0,0,3,0,5,0,11,15,9,0,
/// 0,0,0,12,11,0,2,0,0,0,0,0,0,0,0,0,
/// 0,8,0,0,6,14,1,0,13,15,0,0,0,0,0,10,
/// 10,0,0,3,9,0,7,0,0,1,0,0,13,12,8,0,
/// 7,0,0,0,0,0,14,0,0,0,0,0,0,0,0,9,
/// 0,3,0,14,0,0,9,6,0,0,0,0,0,4,0,0,
/// 0,4,6,0,0,7,0,0,0,0,0,0,0,0,0,0,
/// 5,2,0,0,0,4,10,15,1,0,3,0,0,0,7,0,
/// ];
impl SField { impl SField {
pub fn new() -> SField { pub fn new() -> SField {
let field = vec![0; SIZE * SIZE]; #[rustfmt::skip]
let field = vec![
0,0,0,0,0,0,0,0,0,
0,0,0,0,8,9,0,0,0,
0,0,0,0,2,0,4,0,0,
0,0,4,0,6,0,0,0,8,
0,0,0,5,0,0,0,0,0,
0,6,5,0,0,2,0,7,4,
0,3,0,0,0,5,0,4,0,
0,0,1,8,0,0,0,0,0,
0,0,8,2,0,0,0,6,0,
];
let mut fixed = Vec::with_capacity(SIZE * SIZE); let mut sudoku = SField {
field.iter().for_each(|e| {
if *e == 0 {
fixed.push(false);
} else {
fixed.push(true);
}
});
SField {
field, field,
fixed, skip_forward: vec![0; NUM_FIELDS + 1],
size: SIZE, skip_backward: vec![0; NUM_FIELDS + 1],
block_size: BLOCK_SIZE,
pos: 0, pos: 0,
pos_last_placed: 0, possible_values: vec![vec![]; NUM_FIELDS],
num_fields: SIZE * SIZE, };
possible_values: vec![vec![]; SIZE * SIZE],
sudoku.build_possible_values_db();
sudoku.build_skip_dbs();
sudoku
}
fn build_skip_dbs(&mut self) {
fn find_fixed_streak_forward(mut idx: usize, field: &[u8]) -> u8 {
let mut fixed_count = 1;
idx += 1;
while idx < NUM_FIELDS && field[idx] > 0 {
fixed_count += 1;
idx += 1;
}
fixed_count
}
fn find_fixed_streak_backward(mut idx: usize, field: &[u8]) -> u8 {
let mut fixed_count = 1;
idx -= 1;
while idx < NUM_FIELDS && field[idx] > 0 {
fixed_count += 1;
idx -= 1;
}
fixed_count
}
let fwd = &mut self.skip_forward;
for (idx, nr) in self.field.iter().enumerate() {
match nr {
0 => fwd[idx] = *nr,
_ => fwd[idx] = find_fixed_streak_forward(idx, &self.field),
}
}
let bwd = &mut self.skip_backward;
for (idx, nr) in self.field.iter().enumerate().rev() {
match nr {
0 => bwd[idx + 1] = *nr,
_ => bwd[idx + 1] = find_fixed_streak_backward(idx, &self.field),
}
} }
} }
fn build_possible_values_db(&mut self) { fn build_possible_values_db(&mut self) {
for idx in 0..self.num_fields { for idx in 0..NUM_FIELDS {
if self.fixed[idx] { if self.field[idx] != 0 {
continue; continue;
} }
self.pos = idx; self.pos = idx;
// try all values between 1 and =self.size and remember the good ones // try all values between 1 and =self.size and remember the good ones
let mut good_ones = Vec::with_capacity(self.size); let mut good_ones = Vec::with_capacity(SIZE);
for nr in 1..=(self.size as u8) { for nr in 1..=(u8::try_from(SIZE).expect("SIZE is too big")) {
if self.ok(nr) { if self.ok(nr) {
good_ones.push(nr); good_ones.push(nr);
} }
@ -126,188 +119,70 @@ impl SField {
} }
pub fn solve_backtracking(&mut self) -> bool { pub fn solve_backtracking(&mut self) -> bool {
let mut found_solution = false;
let mut num_solutions = 0; let mut num_solutions = 0;
let mut last_num_solutions = num_solutions;
let mut loop_count = 0;
let mut last_loop_count = loop_count;
let mut now = Instant::now();
loop { loop {
loop_count += 1; if !self.put_valid_nr() {
const MILLIS_PER_SEC: u128 = 1_000;
const UPDATE_DELAY_MS: u128 = 80;
if loop_count % 1000 == 0 {
let elapsed_ms = now.elapsed().as_millis();
if elapsed_ms <= UPDATE_DELAY_MS {
continue;
}
self.print_clear();
self.print();
println!(
"{} loops/sec",
(loop_count - last_loop_count) * (MILLIS_PER_SEC / elapsed_ms)
);
println!(
"{} solutions/sec",
(num_solutions - last_num_solutions) * (MILLIS_PER_SEC / elapsed_ms)
);
last_loop_count = loop_count;
last_num_solutions = num_solutions;
now = Instant::now();
}
if self.is_end() {
found_solution = true;
num_solutions += 1;
/*
if num_solutions % 100 == 0 {
self.print_clear();
println!("Solutions: {}", num_solutions);
self.print();
}
*/
if self.is_fixed() {
continue;
}
self.clear_current_field(); self.clear_current_field();
self.prev(); if !self.prev() {
self.goto_prev_free_field(); print_clear();
} self.print();
println!("Number of solutions: {num_solutions}");
if self.is_fixed() { break;
self.next(); }
continue; continue;
} }
if self.goto_next_free_field() { if !self.next() {
if self.put_valid_nr() { num_solutions += 1;
self.next(); if num_solutions % 10_000 == 0 {
continue; print_clear();
} else { self.print();
//println!("put_valid_nr failed for pos {}", self.pos); println!("Number of solutions: {num_solutions}");
//std::thread::sleep_ms(300);
self.clear_current_field();
if !self.prev() {
println!("Number of solutions: {}", num_solutions);
break;
}
if !self.goto_prev_free_field() {
println!("Number of solutions: {}", num_solutions);
break;
}
} }
self.clear_current_field();
self.prev();
} }
} }
found_solution num_solutions > 0
} }
#[inline(always)]
fn print_gray(&self) {
print!("\x1b\x5b\x31\x3b\x33\x30\x6d");
}
#[inline(always)]
fn print_green(&self) {
print!("\x1b\x5b\x31\x3b\x33\x32\x6d");
}
#[inline(always)]
fn print_red(&self) {
print!("\x1b\x5b\x31\x3b\x33\x31\x6d");
}
#[inline(always)]
fn print_neutral(&self) {
print!("\x1b\x5b\x31\x3b\x30\x6d");
}
#[inline(always)]
fn print_clear(&self) {
print!("\x1b\x5b\x48\x1b\x5b\x32\x4a");
}
#[inline(always)]
fn print(&self) { fn print(&self) {
for i in 0..self.num_fields { for i in 0..NUM_FIELDS {
if i != 0 && i % self.size == 0 { if i != 0 && i % SIZE == 0 {
println!(); println!();
} }
if i == self.pos_last_placed { if i == self.pos {
self.print_red(); print_green();
} else if i == self.pos {
self.print_green();
} else if self.get_field_at_pos(i) == 0 { } else if self.get_field_at_pos(i) == 0 {
self.print_gray(); print_gray();
} }
print!("{:2} ", self.get_field_at_pos(i)); print!("{:2} ", self.get_field_at_pos(i));
if i == self.pos || i == self.pos_last_placed || self.get_field_at_pos(i) == 0 { if i == self.pos || self.get_field_at_pos(i) == 0 {
self.print_neutral(); print_neutral();
} }
} }
println!(); println!();
} }
#[inline(always)]
fn clear_current_field(&mut self) { fn clear_current_field(&mut self) {
self.set(0); self.set(0);
} }
#[inline(always)]
fn goto_prev_free_field(&mut self) -> bool {
while {
if !self.is_fixed() {
return true;
}
self.prev()
} {}
false
}
#[inline(always)]
fn goto_next_free_field(&mut self) -> bool {
while {
if !self.is_fixed() {
return true;
}
self.next()
} {}
false
}
#[inline(always)]
fn _put_valid_nr(&mut self) -> bool {
let current_nr = self.get_field_at_pos(self.pos);
for nr in current_nr..(self.size + 1) as u8 {
if self.ok(nr) {
self.set(nr);
return true;
}
}
false
}
#[inline(always)]
fn put_valid_nr(&mut self) -> bool { fn put_valid_nr(&mut self) -> bool {
let current_nr = self.get_field_at_pos(self.pos); let current_nr = self.get_field_at_pos(self.pos);
// safety: // safety:
// self.possible_vals is initialized with self.size * self.size // self.possible_vals is initialized with self.size * self.size
// so self.pos can safely be used to index here // so self.pos can safely be used to index here
let possible_vals = unsafe { self.possible_values.get_unchecked(self.pos) }; let possible_vals = &self.possible_values[self.pos];
for nr in possible_vals.iter() { for nr in possible_vals {
if *nr <= current_nr { if *nr <= current_nr {
continue; continue;
} }
@ -320,32 +195,10 @@ impl SField {
false false
} }
#[inline(always)]
fn is_end(&self) -> bool {
!self.field.contains(&0)
}
#[inline(always)]
fn ok(&self, nr: u8) -> bool { fn ok(&self, nr: u8) -> bool {
self.block_ok(nr) && self.row_ok(nr) && self.col_ok(nr) self.block_ok(nr) && self.row_ok(nr) && self.col_ok(nr)
} }
#[inline(always)]
fn _pos_to_xy(&self) -> (usize, usize) {
let y = self.pos / self.size;
let x = self.pos % self.size;
(x + 1, y + 1)
}
#[inline(always)]
fn is_fixed(&self) -> bool {
// safety: self.pos can be used to index the field unchecked
// since the only methods modifying self.pos are
// `next()` and `prev()` and they do bounds checking
unsafe { *self.fixed.get_unchecked(self.pos) }
}
#[inline(always)]
fn get_field_at_pos(&self, pos: usize) -> u8 { fn get_field_at_pos(&self, pos: usize) -> u8 {
// safety: // safety:
// TODO // TODO
@ -354,81 +207,74 @@ impl SField {
unsafe { *self.field.get_unchecked(pos) } unsafe { *self.field.get_unchecked(pos) }
} }
#[inline(always)]
fn set(&mut self, nr: u8) { fn set(&mut self, nr: u8) {
self.field[self.pos] = nr; self.field[self.pos] = nr;
self.pos_last_placed = self.pos;
} }
#[inline(always)]
fn get_row(&self, row: &mut [u8; SIZE]) { fn get_row(&self, row: &mut [u8; SIZE]) {
for (idx, row_elem) in row.iter_mut().enumerate() { for (idx, row_elem) in row.iter_mut().enumerate() {
*row_elem = self.get_field_at_pos((self.pos / self.size) * self.size + idx); *row_elem = self.get_field_at_pos((self.pos / SIZE) * SIZE + idx);
} }
} }
#[inline(always)]
fn get_col(&self, col: &mut [u8; SIZE]) { fn get_col(&self, col: &mut [u8; SIZE]) {
for (idx, col_elem) in col.iter_mut().enumerate() { for (idx, col_elem) in col.iter_mut().enumerate() {
*col_elem = self.get_field_at_pos(idx * self.size + self.pos % self.size); *col_elem = self.get_field_at_pos(idx * SIZE + self.pos % SIZE);
} }
} }
#[inline(always)]
fn get_block(&self, block: &mut [u8; SIZE]) { fn get_block(&self, block: &mut [u8; SIZE]) {
let block_start_row = self.pos / self.size / self.block_size * self.block_size; let block_start_row = self.pos / SIZE / BLOCK_SIZE * BLOCK_SIZE;
let block_start_col = self.pos % self.size / self.block_size * self.block_size; let block_start_col = self.pos % SIZE / BLOCK_SIZE * BLOCK_SIZE;
for r in 0..self.block_size { for r in 0..BLOCK_SIZE {
for c in 0..self.block_size { for c in 0..BLOCK_SIZE {
block[r * self.block_size + c] = block[r * BLOCK_SIZE + c] =
self.get_field_at_pos(self.size * (block_start_row + r) + block_start_col + c); self.get_field_at_pos(SIZE * (block_start_row + r) + block_start_col + c);
} }
} }
} }
#[inline(always)]
fn block_ok(&self, nr: u8) -> bool { fn block_ok(&self, nr: u8) -> bool {
let mut block = [0; SIZE]; let mut block = [0; SIZE];
self.get_block(&mut block); self.get_block(&mut block);
!block.contains(&nr) !block.contains(&nr)
} }
#[inline(always)]
fn row_ok(&self, nr: u8) -> bool { fn row_ok(&self, nr: u8) -> bool {
let mut row = [0; SIZE]; let mut row = [0; SIZE];
self.get_row(&mut row); self.get_row(&mut row);
!row.contains(&nr) !row.contains(&nr)
} }
#[inline(always)]
fn col_ok(&self, nr: u8) -> bool { fn col_ok(&self, nr: u8) -> bool {
let mut col = [0; SIZE]; let mut col = [0; SIZE];
self.get_col(&mut col); self.get_col(&mut col);
!col.contains(&nr) !col.contains(&nr)
} }
#[inline(always)]
fn next(&mut self) -> bool { fn next(&mut self) -> bool {
if self.pos == self.num_fields - 1 { let new_pos = self.pos + 1 + self.skip_forward[self.pos + 1] as usize;
if new_pos >= NUM_FIELDS {
return false; return false;
} }
self.pos += 1; self.pos = new_pos;
true true
} }
#[inline(always)]
fn prev(&mut self) -> bool { fn prev(&mut self) -> bool {
if self.pos == 0 { let new_pos = self.pos - 1 - self.skip_backward[self.pos] as usize;
if new_pos >= NUM_FIELDS {
return false; return false;
} }
self.pos -= 1; self.pos = new_pos;
true true
} }
#[inline(always)]
fn solve(&mut self) { fn solve(&mut self) {
let now = Instant::now(); let now = Instant::now();
if !self.solve_backtracking() { if !self.solve_backtracking() {
@ -438,17 +284,7 @@ impl SField {
} }
} }
fn run() -> Result<(), String> {
let mut field = SField::new();
field.build_possible_values_db();
field.solve();
Ok(())
}
fn main() { fn main() {
if let Err(e) = run() { let mut field = SField::new();
println!("{}", e) field.solve();
}
} }