Merge remote-tracking branch 'public/satisfiability/sat_global_opt'

tig-algorithms/src/satisfiability/mod.rs

@@ -86,7 +86,8 @@ pub use sat_global as c001_a034;
 
 // c001_a040
 
-// c001_a041
+pub mod sat_global_opt;
+pub use sat_global_opt as c001_a041;
 
 // c001_a042
 

tig-algorithms/src/satisfiability/sat_global_opt/benchmarker_outbound.rs

@@ -0,0 +1,292 @@
+/*!
+Copyright 2024 syebastian
+
+Licensed under the TIG Benchmarker Outbound Game License v1.0 (the "License"); you 
+may not use this file except in compliance with the License. You may obtain a copy 
+of the License at
+
+https://github.com/tig-foundation/tig-monorepo/tree/main/docs/licenses
+
+Unless required by applicable law or agreed to in writing, software distributed
+under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+CONDITIONS OF ANY KIND, either express or implied. See the License for the specific
+language governing permissions and limitations under the License.
+*/
+
+use rand::{rngs::{SmallRng, StdRng}, Rng, SeedableRng};
+use std::collections::HashMap;
+use tig_challenges::satisfiability::*;
+
+pub fn solve_challenge(challenge: &Challenge) -> anyhow::Result<Option<Solution>> {
+    let mut rng = SmallRng::seed_from_u64(u64::from_le_bytes(challenge.seed[..8].try_into().unwrap()) as u64);
+
+    let mut p_single = vec![false; challenge.difficulty.num_variables];
+    let mut n_single = vec![false; challenge.difficulty.num_variables];
+
+    let mut clauses_ = challenge.clauses.clone();
+    let mut clauses: Vec<Vec<i32>> = Vec::with_capacity(clauses_.len());
+
+    let mut rounds = 0;
+
+    let mut dead = false;
+
+    while !(dead) {
+        let mut done = true;
+        for c in &clauses_ {
+            let mut c_: Vec<i32> = Vec::with_capacity(c.len()); // Preallocate with capacity
+            let mut skip = false;
+            for (i, l) in c.iter().enumerate() {
+                if (p_single[(l.abs() - 1) as usize] && *l > 0)
+                    || (n_single[(l.abs() - 1) as usize] && *l < 0)
+                    || c[(i + 1)..].contains(&-l)
+                {
+                    skip = true;
+                    break;
+                } else if p_single[(l.abs() - 1) as usize]
+                    || n_single[(l.abs() - 1) as usize]
+                    || c[(i + 1)..].contains(&l)
+                {
+                    done = false;
+                    continue;
+                } else {
+                    c_.push(*l);
+                }
+            }
+            if skip {
+                done = false;
+                continue;
+            };
+            match c_[..] {
+                [l] => {
+                    done = false;
+                    if l > 0 {
+                        if n_single[(l.abs() - 1) as usize] {
+                            dead = true;
+                            break;
+                        } else {
+                            p_single[(l.abs() - 1) as usize] = true;
+                        }
+                    } else {
+                        if p_single[(l.abs() - 1) as usize] {
+                            dead = true;
+                            break;
+                        } else {
+                            n_single[(l.abs() - 1) as usize] = true;
+                        }
+                    }
+                }
+                [] => {
+                    dead = true;
+                    break;
+                }
+                _ => {
+                    clauses.push(c_);
+                }
+            }
+        }
+        if done {
+            break;
+        } else {
+            clauses_ = clauses;
+            clauses = Vec::with_capacity(clauses_.len());
+        }
+    }
+
+    if dead {
+        return Ok(None);
+    }
+
+    let num_variables = challenge.difficulty.num_variables;
+    let num_clauses = clauses.len();
+
+    let mut p_clauses: Vec<Vec<usize>> = vec![Vec::new(); num_variables];
+    let mut n_clauses: Vec<Vec<usize>> = vec![Vec::new(); num_variables];
+
+    // Preallocate capacity for p_clauses and n_clauses
+    for c in &clauses {
+        for &l in c {
+            let var = (l.abs() - 1) as usize;
+            if l > 0 {
+                if p_clauses[var].capacity() == 0 {
+                    p_clauses[var] = Vec::with_capacity(clauses.len() / num_variables + 1);
+                }
+            } else {
+                if n_clauses[var].capacity() == 0 {
+                    n_clauses[var] = Vec::with_capacity(clauses.len() / num_variables + 1);
+                }
+            }
+        }
+    }
+
+    for (i, &ref c) in clauses.iter().enumerate() {
+        for &l in c {
+            let var = (l.abs() - 1) as usize;
+            if l > 0 {
+                p_clauses[var].push(i);
+            } else {
+                n_clauses[var].push(i);
+            }
+        }
+    }
+
+    let mut variables = vec![false; num_variables];
+    for v in 0..num_variables {
+        let num_p = p_clauses[v].len();
+        let num_n = n_clauses[v].len();
+
+        let nad = 1.28;
+        let mut vad = nad + 1.0;
+        if num_n > 0 {
+            vad = num_p as f32 / num_n as f32;
+        }
+
+        if vad <= nad {
+            variables[v] = false;
+        } else {
+            let prob = num_p as f64 / (num_p + num_n).max(1) as f64;
+            variables[v] = rng.gen_bool(prob)
+        }
+    }
+
+    let mut num_good_so_far: Vec<u8> = vec![0; num_clauses];
+    for (i, &ref c) in clauses.iter().enumerate() {
+        for &l in c {
+            let var = (l.abs() - 1) as usize;
+            if l > 0 && variables[var] {
+                num_good_so_far[i] += 1
+            } else if l < 0 && !variables[var] {
+                num_good_so_far[i] += 1
+            }
+        }
+    }
+
+
+    let mut residual_ = Vec::with_capacity(num_clauses);
+    let mut residual_indices = vec![None; num_clauses];
+
+    for (i, &num_good) in num_good_so_far.iter().enumerate() {
+        if num_good == 0 {
+            residual_.push(i);
+            residual_indices[i] = Some(residual_.len() - 1);
+        }
+    }
+
+    let clauses_ratio = challenge.difficulty.clauses_to_variables_percent as f64;
+    let num_vars = challenge.difficulty.num_variables as f64;
+    let max_fuel = 2000000000.0;
+    let base_fuel = (2000.0 + 40.0 * clauses_ratio) * num_vars;
+    let flip_fuel = 350.0 + 0.9 * clauses_ratio;
+    let max_num_rounds = ((max_fuel - base_fuel) / flip_fuel) as usize;
+    loop {
+        if !residual_.is_empty() {
+
+            let rand_val = rng.gen::<usize>();
+
+            let i = residual_[rand_val % residual_.len()];
+            let mut min_sad = clauses.len();
+            let mut v_min_sad = usize::MAX;
+            let c = &mut clauses[i];
+
+            if c.len() > 1 {
+                let random_index = rand_val % c.len();
+                c.swap(0, random_index);
+            }
+            for &l in c.iter() {
+                let abs_l = l.abs() as usize - 1;
+                let clauses_to_check = if variables[abs_l] { &p_clauses[abs_l] } else { &n_clauses[abs_l] };
+
+                let mut sad = 0;
+                for &c in clauses_to_check {
+                    if num_good_so_far[c] == 1 {
+                        sad += 1;
+                    }
+                }
+
+                if sad < min_sad {
+                    min_sad = sad;
+                    v_min_sad = abs_l;
+                }
+            }
+
+            let v = if min_sad == 0 {
+                v_min_sad
+            } else if rng.gen_bool(0.5) {
+                c[0].abs() as usize - 1
+            } else {
+                v_min_sad
+            };
+
+            if variables[v] {
+                for &c in &n_clauses[v] {
+                    num_good_so_far[c] += 1;
+                    if num_good_so_far[c] == 1 {
+                        let i = residual_indices[c].take().unwrap();
+                        let last = residual_.pop().unwrap();
+                        if i < residual_.len() {
+                            residual_[i] = last;
+                            residual_indices[last] = Some(i);
+                        }
+                    }
+                }
+                for &c in &p_clauses[v] {
+                    if num_good_so_far[c] == 1 {
+                        residual_.push(c);
+                        residual_indices[c] = Some(residual_.len() - 1);
+                    }
+                    num_good_so_far[c] -= 1;
+                }
+            } else {
+                for &c in &n_clauses[v] {
+                    if num_good_so_far[c] == 1 {
+                        residual_.push(c);
+                        residual_indices[c] = Some(residual_.len() - 1);
+                    }
+                    num_good_so_far[c] -= 1;
+                }
+
+                for &c in &p_clauses[v] {
+                    num_good_so_far[c] += 1;
+                    if num_good_so_far[c] == 1 {
+                        let i = residual_indices[c].take().unwrap();
+                        let last = residual_.pop().unwrap();
+                        if i < residual_.len() {
+                            residual_[i] = last;
+                            residual_indices[last] = Some(i);
+                        }
+                    }
+                }
+            }
+
+            variables[v] = !variables[v];
+        } else {
+            break;
+        }
+        rounds += 1;
+        if rounds >= max_num_rounds {
+            return Ok(None);
+        }
+    }
+    return Ok(Some(Solution { variables }));
+}
+
+#[cfg(feature = "cuda")]
+mod gpu_optimisation {
+    use super::*;
+    use cudarc::driver::*;
+    use std::{collections::HashMap, sync::Arc};
+    use tig_challenges::CudaKernel;
+
+    // set KERNEL to None if algorithm only has a CPU implementation
+    pub const KERNEL: Option<CudaKernel> = None;
+
+    // Important! your GPU and CPU version of the algorithm should return the same result
+    pub fn cuda_solve_challenge(
+        challenge: &Challenge,
+        dev: &Arc<CudaDevice>,
+        mut funcs: HashMap<&'static str, CudaFunction>,
+    ) -> anyhow::Result<Option<Solution>> {
+        solve_challenge(challenge)
+    }
+}
+#[cfg(feature = "cuda")]
+pub use gpu_optimisation::{cuda_solve_challenge, KERNEL};