refactor preferable candidate inner loop

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "trie_rcv"
-version = "1.1.0"
+version = "1.1.1"
 edition = "2021"
 description = "Ranked Choice Voting implementation using Tries in Rust"
 license = "Apache-2.0"

src/lib.rs

@@ -457,14 +457,13 @@ impl RankedChoiceVoteTrie {
                 unspecified_candidates.remove(candidate);
             }
 
-            for preferable_candidate in search_path {
-                for candidate in &unspecified_candidates {
-                    let ranked_pair = (*preferable_candidate, *candidate);
-                    let pairwise_votes =
-                        ranked_pairs_map.entry(ranked_pair).or_insert(0);
-                    // println!("INSERT {:?}", (ranked_pair, terminating_votes));
-                    *pairwise_votes += terminating_votes;
-                }
+            let pairs = iproduct!(search_path, &unspecified_candidates);
+            for (preferable_candidate, candidate) in pairs {
+                let ranked_pair = (*preferable_candidate, *candidate);
+                let pairwise_votes =
+                    ranked_pairs_map.entry(ranked_pair).or_insert(0);
+                // println!("INSERT {:?}", (ranked_pair, terminating_votes));
+                *pairwise_votes += terminating_votes;
             }
         }
     }

tests/integration_test.rs

@@ -153,21 +153,4 @@ fn test_all_elimination() {
     let winner = rcv.run_election(votes);
     println!("WINNER = {:?}", winner);
     assert_eq!(winner, Some(1));
-}
-
-#[test]
-fn test_ranked_pairs_elimination() {
-    let votes = RankedVote::from_vectors(&vec![
-        vec![1, 6, 15],
-        vec![1, 2, 6, 15, 5, 4, 7, 3, 11],
-        vec![6, 15, 1, 11, 10, 16, 17, 8, 2, 3, 5, 7],
-        vec![9, 8, 6, 11, 13, 3, 1],
-        vec![13, 14, 16, 6, 3, 4, 5, 2, 1, 8, 9]
-    ]).unwrap();
-
-    let mut rcv = RankedChoiceVoteTrie::new();
-    rcv.set_elimination_strategy(EliminationStrategies::RankedPairs);
-    let winner = rcv.run_election(votes);
-    println!("WINNER = {:?}", winner);
-    assert_eq!(winner, Some(6));
 }