From 092d75dbbbe77a70a3b70f1c0b6f356f36a5e8a1 Mon Sep 17 00:00:00 2001
From: Kiana Sheibani <kiana.a.sheibani@gmail.com>
Date: Sat, 18 Nov 2023 20:43:26 -0500
Subject: [PATCH] Use Dijkstra's algorithm to construct hyp. adv.

---
 src/datasets.rs | 129 +++++++++++++++++++++++++++++++-----------------
 1 file changed, 84 insertions(+), 45 deletions(-)

diff --git a/src/datasets.rs b/src/datasets.rs
index d726159..06f19b7 100644
--- a/src/datasets.rs
+++ b/src/datasets.rs
@@ -413,11 +413,13 @@ pub fn get_edges(
     connection: &Connection,
     dataset: &str,
     player: PlayerId,
-) -> sqlite::Result<Vec<(PlayerId, f64)>> {
+) -> sqlite::Result<Vec<(PlayerId, f64, u64)>> {
     let query = format!(
-        r#"SELECT iif(:pl = player_B, player_A, player_B) AS id, iif(:pl = player_B, -advantage, advantage) AS advantage
-            FROM "{}_network"
-            WHERE player_A = :pl OR player_B = :pl"#,
+        r#"SELECT
+    iif(:pl = player_B, player_A, player_B) AS id,
+    iif(:pl = player_B, -advantage, advantage) AS advantage, sets_count
+    FROM "{}_network"
+    WHERE player_A = :pl OR player_B = :pl"#,
         dataset
     );
 
@@ -430,6 +432,7 @@ pub fn get_edges(
             Ok((
                 PlayerId(r_.read::<i64, _>("id") as u64),
                 r_.read::<f64, _>("advantage"),
+                r_.read::<i64, _>("sets_count") as u64,
             ))
         })
         .try_collect()
@@ -462,64 +465,82 @@ pub fn either_isolated(
 pub fn hypothetical_advantage(
     connection: &Connection,
     dataset: &str,
-    decay_rate: f64,
     player1: PlayerId,
     player2: PlayerId,
+    set_limit: u64,
+    decay_rate: f64,
+    adj_decay_rate: f64,
 ) -> sqlite::Result<f64> {
-    use std::collections::HashSet;
+    use std::collections::{HashMap, HashSet};
+
     // Check trivial cases
     if player1 == player2 || either_isolated(connection, dataset, player1, player2)? {
         return Ok(0.0);
     }
 
-    let mut paths: Vec<(Vec<PlayerId>, f64)> = vec![(vec![player1], 0.0)];
     let mut visited: HashSet<PlayerId> = HashSet::new();
+    let mut queue: HashMap<PlayerId, (f64, f64)> = HashMap::from([(player1, (0.0, 1.0))]);
 
-    let mut final_path: Option<(f64, usize)> = None;
+    while !queue.is_empty() {
+        let visiting = *queue
+            .iter()
+            .max_by(|a, b| a.1 .1.partial_cmp(&b.1 .1).unwrap())
+            .unwrap()
+            .0;
+        let (adv_v, decay_v) = queue.remove(&visiting).unwrap();
+        let connections = get_edges(connection, dataset, visiting)?;
 
-    while final_path.is_none() {
-        if paths.is_empty() {
-            return Ok(0.0);
-        }
-        paths = paths
+        for (id, adv, sets) in connections
             .into_iter()
-            .map(|(path, old_adv)| {
-                let last = *path.last().unwrap();
-                Ok(get_edges(connection, dataset, last)?
-                    .into_iter()
-                    .filter_map(|(id, adv)| {
-                        if visited.contains(&id) {
-                            None
-                        } else {
-                            if id == player2 {
-                                final_path = Some((old_adv + adv, path.len() - 1));
-                            }
-                            visited.insert(id);
-                            let mut path_ = path.clone();
-                            path_.extend_one(id);
-                            Some((path_, old_adv + adv))
-                        }
-                    })
-                    .collect::<Vec<_>>())
-            })
-            .try_fold(Vec::new(), |mut acc, paths| {
-                acc.extend(paths?);
-                Ok(acc)
-            })?;
+            .filter(|(id, _, _)| !visited.contains(id))
+        {
+            let advantage = adv_v + adv;
+
+            if id == player2 {
+                return Ok(advantage * decay_v);
+            }
+
+            let decay = decay_v
+                * if sets >= set_limit {
+                    decay_rate
+                } else {
+                    adj_decay_rate
+                };
+
+            if queue
+                .get(&id)
+                .map(|(_, decay_old)| *decay_old < decay)
+                .unwrap_or(true)
+            {
+                queue.insert(id, (advantage, decay));
+            }
+        }
+
+        visited.insert(visiting);
     }
 
-    let (final_adv, len) = final_path.unwrap();
-    Ok(final_adv * decay_rate.powi(len as i32))
+    // No path found
+    Ok(0.0)
 }
 
 pub fn initialize_edge(
     connection: &Connection,
     dataset: &str,
-    decay_rate: f64,
     player1: PlayerId,
     player2: PlayerId,
+    set_limit: u64,
+    decay_rate: f64,
+    adj_decay_rate: f64,
 ) -> sqlite::Result<f64> {
-    let adv = hypothetical_advantage(connection, dataset, decay_rate, player1, player2)?;
+    let adv = hypothetical_advantage(
+        connection,
+        dataset,
+        player1,
+        player2,
+        set_limit,
+        decay_rate,
+        adj_decay_rate,
+    )?;
     insert_advantage(connection, dataset, player1, player2, adv)?;
     Ok(adv)
 }
@@ -644,15 +665,15 @@ CREATE TABLE IF NOT EXISTS datasets (
 
         assert_eq!(
             get_edges(&connection, "test", PlayerId(1))?,
-            [(PlayerId(2), -1.0), (PlayerId(3), 5.0)]
+            [(PlayerId(2), -1.0, 0), (PlayerId(3), 5.0, 0)]
         );
         assert_eq!(
             get_edges(&connection, "test", PlayerId(2))?,
-            [(PlayerId(1), 1.0)]
+            [(PlayerId(1), 1.0, 0)]
         );
         assert_eq!(
             get_edges(&connection, "test", PlayerId(3))?,
-            [(PlayerId(1), -5.0)]
+            [(PlayerId(1), -5.0, 0)]
         );
         Ok(())
     }
@@ -670,10 +691,19 @@ CREATE TABLE IF NOT EXISTS datasets (
             Timestamp(0),
         )?;
 
+        let metadata = metadata();
         for i in 1..=num_players {
             for j in 1..=num_players {
                 assert_eq!(
-                    hypothetical_advantage(&connection, "test", 0.5, PlayerId(i), PlayerId(j))?,
+                    hypothetical_advantage(
+                        &connection,
+                        "test",
+                        PlayerId(i),
+                        PlayerId(j),
+                        metadata.set_limit,
+                        metadata.decay_rate,
+                        metadata.adj_decay_rate
+                    )?,
                     0.0
                 );
             }
@@ -690,8 +720,17 @@ CREATE TABLE IF NOT EXISTS datasets (
 
         insert_advantage(&connection, "test", PlayerId(1), PlayerId(2), 1.0)?;
 
+        let metadata = metadata();
         assert_eq!(
-            hypothetical_advantage(&connection, "test", 0.5, PlayerId(1), PlayerId(2))?,
+            hypothetical_advantage(
+                &connection,
+                "test",
+                PlayerId(1),
+                PlayerId(2),
+                metadata.set_limit,
+                metadata.decay_rate,
+                metadata.adj_decay_rate
+            )?,
             1.0
         );