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-rw-r--r--spec/util_indexedbheap_spec.lua33
-rw-r--r--util/indexedbheap.lua2
2 files changed, 34 insertions, 1 deletions
diff --git a/spec/util_indexedbheap_spec.lua b/spec/util_indexedbheap_spec.lua
new file mode 100644
index 00000000..b10ee385
--- /dev/null
+++ b/spec/util_indexedbheap_spec.lua
@@ -0,0 +1,33 @@
+local ibh = require"util.indexedbheap";
+
+local function verify_heap_property(priorities)
+ for k in ipairs(priorities) do
+ local parent = priorities[k];
+ local childA = priorities[2*k];
+ local childB = priorities[2*k+1];
+ -- print("-", parent, childA, childB)
+ assert(childA == nil or childA > parent, "heap property violated");
+ assert(childB == nil or childB > parent, "heap property violated");
+ end
+end
+
+local h
+setup(function ()
+ h = ibh.create();
+end)
+describe("util.indexedbheap", function ()
+ it("item can be moved from end to top", function ()
+ verify_heap_property(h);
+ h:insert("a", 1);
+ verify_heap_property(h);
+ h:insert("b", 2);
+ verify_heap_property(h);
+ h:insert("c", 3);
+ verify_heap_property(h);
+ local id = h:insert("*", 10);
+ verify_heap_property(h);
+ h:reprioritize(id, 0);
+ verify_heap_property(h);
+ assert.same({ 0, "*", id }, { h:pop() });
+ end)
+end);
diff --git a/util/indexedbheap.lua b/util/indexedbheap.lua
index 7f193d54..45830673 100644
--- a/util/indexedbheap.lua
+++ b/util/indexedbheap.lua
@@ -23,7 +23,7 @@ local function _percolate_up(self, k, sync, index)
local tmp_sync = sync[k];
while k ~= 1 do
local parent = math_floor(k/2);
- if tmp < self[parent] then break; end
+ if tmp >= self[parent] then break; end
self[k] = self[parent];
sync[k] = sync[parent];
index[sync[k]] = k;