# UNDF: UNDF-2026-000000004
Fixes angelscript-0003: CompileSwitch — caseValues.IndexOf() O(n) inside while loop
over switch cases. Duplicate detection is O(n²) for switch statements.

--- a/source/as_compiler.cpp
+++ b/source/as_compiler.cpp
@@ -4020,6 +4020,7 @@ void asCCompiler::CompileSwitch(...)
 	asCArray<int>    caseValues;
 	asCArray<int>    caseLabels;
+	asCSet<asDWORD>  caseValueSet;   // FIX angelscript-0003: O(1) dup check — CWE-407

 	// Compile all case comparisons and make them jump to the right label
 	asCScriptNode *cnode = snode->firstChild->next;
 	while( cnode )
 	{
 		// ...
-		// Has this case been declared already?
-		if (caseValues.IndexOf(c.type.GetConstantDW()) >= 0)   // O(n) — CWE-407
+		// Has this case been declared already?
+		if (caseValueSet.Exists(c.type.GetConstantDW()))        // O(1) — fixed
 			Error(TXT_DUPLICATE_SWITCH_CASE, cnode->firstChild);

 		// Store constant for later use
 		caseValues.PushLast(c.type.GetConstantDW());
+		caseValueSet.Insert(c.type.GetConstantDW());