Fixing bug in numeric comparator of recodex token judge.

judges/recodex_token_judge/comparator.hpp

@@ -185,7 +185,11 @@ template <typename CHAR = char, typename OFFSET = std::uint32_t> class TokenComp
 
 			double d1, d2;
 			if (tokenPair.tryGetFloats(d1, d2)) {
-				double err = std::abs(d1 - d2) / std::abs(d1 + d2);
+				// Divisor (normalizer) must not be zero, so we apply lower bound on it.
+				double divisorLimit = std::max(mFloatTolerance, 0.0001);
+				double divisor = std::max(std::abs(d1) + std::abs(d2), divisorLimit);
+
+				double err = std::abs(d1 - d2) / divisor;
 				return err <= mFloatTolerance;
 			}
 		}

judges/recodex_token_judge/recodex-token-judge.cpp

@@ -39,7 +39,7 @@ int main(int argc, char *argv[])
 		args.registerArg(bpp::make_unique<bpp::ProgramArguments::ArgBool>(
 			"numeric", "Tokens which appear to be integers or floats in decimal notation are compared as numbers."));
 		args.registerArg(bpp::make_unique<bpp::ProgramArguments::ArgFloat>("float-tolerance",
-			"Allowed maximal error for float number comparisons. The error of two numbers is |a-b|/|a+b|.",
+			"Allowed maximal error for float number comparisons. The error of two numbers is |a-b|/(|a|+|b|).",
 			false,
 			0.0001,
 			0.0,

judges/recodex_token_judge/tests/05-numeric.bats

@@ -15,6 +15,6 @@ load bats-shared
 }
 
 @test "numeric float tolerance" {
-	run $EXE_FILE --numeric --float-tolerance 0.01 $CORRECT_FILE $RESULT_FILE
+	run $EXE_FILE --numeric --float-tolerance 0.001 $CORRECT_FILE $RESULT_FILE
 	[ "$status" -eq 1 ]
 }

judges/recodex_token_judge/tests/05.correct.in

@@ -1,3 +1,4 @@
 some string tokens
 followed by numeric tokens 42 1000000000 +54 -19 0012
 and some float tokens 1.0 1.1 0.001 -0.0002 0.00003
+0

judges/recodex_token_judge/tests/05.error.out

@@ -1,5 +1,7 @@
-0
--2: followed by numeric tokens 42 1000000000 +54 -19 0012
-+2: followed by numeric tokens 42 +1000000000 0054 -19.0 12
--3: and some float tokens 1.0 1.1 0.001 -0.0002 0.00003
-+3: and some float tokens +1.0 1.100 1e-03 -0.0002 0.000031
+0
+-2: followed by numeric tokens 42 1000000000 +54 -19 0012
++2: followed by numeric tokens 42 +1000000000 0054 -19.0 12
+-3: and some float tokens 1.0 1.1 0.001 -0.0002 0.00003
++3: and some float tokens +1.0 1.100 1e-03 -0.0002 0.000031
+-4: 0
++4: 0.00

judges/recodex_token_judge/tests/05.result.in

@@ -1,3 +1,4 @@
 some string tokens
 followed by numeric tokens 42 +1000000000 0054 -19.0 12
 and some float tokens +1.0 1.100 1e-03 -0.0002 0.000031
+0.00