Merge pull request #47 from theSherwood/master

fix: finds the lowest intersecting interval
alexbol99 · Sep 17, 2023 · 45bcbbf · 45bcbbf
2 parents 6a99b44 + c7a577c
commit 45bcbbf
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Showing 2 changed files with 13 additions and 2 deletions.
diff --git a/src/classes/intervalTree.js b/src/classes/intervalTree.js
@@ -422,8 +422,12 @@ class IntervalTree {
         let curr = node;
         while (curr && curr != this.nil_node) {
             if (curr.less_than(search_node)) {
-                if (curr.intersect(search_node) && (!best || curr.less_than(best))) best = curr;
-                curr = curr.right;
+                if (curr.intersect(search_node)) {
+                    best = curr;
+                    curr = curr.left;
+                } else {
+                    curr = curr.right;
+                }
             } else {
                 if (!best || curr.less_than(best)) best = curr;
                 curr = curr.left;

diff --git a/test/intervalTree.js b/test/intervalTree.js
@@ -318,6 +318,13 @@ describe('#IntervalTree', function() {
             let iterator = tree.iterate([3,8]);
             expect(iterator.next().value).to.deep.equal([1,3]);
         });
+        it('Finds the lowest intersecting interval regardless of tree structure', function () {
+            let tree = new IntervalTree();
+            let ints = [[6,8],[5,12],[4,7],[1,5]];
+            for (let int of ints) tree.insert(int);
+            let iterator = tree.iterate([5,5]);
+            expect(iterator.next().value).to.deep.equal([1,5]);
+        });
         it('May find first forward interval when there is no intersection', function () {
             let tree = new IntervalTree();
             let ints = [[6,8],[1,3],[5,12],[1,1],[5,7]];