diff options
author | Haidong Ji | 2018-08-19 15:28:15 -0500 |
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committer | Haidong Ji | 2018-08-19 15:28:15 -0500 |
commit | b3a6f3bc47098c81bef2c7d16690a5801149dbd8 (patch) | |
tree | 6646dbeefa43ec4f8fcc05c47985c1496a8aea76 | |
parent | e56fcf9023ba43919cae20393a2b85d89206271c (diff) |
Least Common Multiple done!
Learned two interesting things:
1. Use GCD to get LCM https://www.idomaths.com/hcflcm.php#formula
2. To make a literal of numbers long, add L at the end of the number!
-rw-r--r-- | AlgoDesignAndTechniqueEdxJava/sources/GcdLcm.java (renamed from AlgoDesignAndTechniqueEdxJava/sources/GCD.java) | 9 | ||||
-rw-r--r-- | AlgoDesignAndTechniqueEdxJava/tests/GCDTest.java | 33 | ||||
-rw-r--r-- | AlgoDesignAndTechniqueEdxJava/tests/GcdLcmTest.java | 48 |
3 files changed, 55 insertions, 35 deletions
diff --git a/AlgoDesignAndTechniqueEdxJava/sources/GCD.java b/AlgoDesignAndTechniqueEdxJava/sources/GcdLcm.java index 5e29e4f..efef982 100644 --- a/AlgoDesignAndTechniqueEdxJava/sources/GCD.java +++ b/AlgoDesignAndTechniqueEdxJava/sources/GcdLcm.java @@ -1,6 +1,6 @@ import java.util.Scanner; -public class GCD { +public class GcdLcm { public static int getGCD(int a, int b) { if (b == 0) { @@ -19,6 +19,11 @@ public class GCD { int a = in.nextInt(); int b = in.nextInt(); - System.out.println(getGCD(a, b)); + System.out.println(getLCM(a, b)); + } + + public static long getLCM(int a, int b) { + // https://www.idomaths.com/hcflcm.php#formula + return (long) a * (long) b / (long) getGCD(a, b); } } diff --git a/AlgoDesignAndTechniqueEdxJava/tests/GCDTest.java b/AlgoDesignAndTechniqueEdxJava/tests/GCDTest.java deleted file mode 100644 index 1c8fedd..0000000 --- a/AlgoDesignAndTechniqueEdxJava/tests/GCDTest.java +++ /dev/null @@ -1,33 +0,0 @@ -import static org.junit.jupiter.api.Assertions.*; -import org.junit.jupiter.api.Test; - -public class GCDTest { - @Test - void testGCD1() { - assertEquals(1, GCD.getGCD(18, 35)); - } - @Test - void testGCD2() { - assertEquals(17657, GCD.getGCD(28851538, 1183019)); - } - - @Test - void testGCD3() { - assertEquals(7, GCD.getGCD(1344, 217)); - } - - @Test - void testGCD4() { - assertEquals(1344, GCD.getGCD(1344, 1344)); - } - - @Test - void testGCD5() { - assertEquals(4, GCD.getGCD(14159572, 63967072)); - } - - @Test - void testGCD6() { - assertEquals(4, GCD.getGCD(63967072,14159572)); - } -} diff --git a/AlgoDesignAndTechniqueEdxJava/tests/GcdLcmTest.java b/AlgoDesignAndTechniqueEdxJava/tests/GcdLcmTest.java new file mode 100644 index 0000000..26806ce --- /dev/null +++ b/AlgoDesignAndTechniqueEdxJava/tests/GcdLcmTest.java @@ -0,0 +1,48 @@ +import static org.junit.jupiter.api.Assertions.*; +import org.junit.jupiter.api.Test; + +public class GcdLcmTest { + @Test + void testGCD1() { + assertEquals(1, GcdLcm.getGCD(18, 35)); + } + @Test + void testGCD2() { + assertEquals(17657, GcdLcm.getGCD(28851538, 1183019)); + } + + @Test + void testGCD3() { + assertEquals(7, GcdLcm.getGCD(1344, 217)); + } + + @Test + void testGCD4() { + assertEquals(1344, GcdLcm.getGCD(1344, 1344)); + } + + @Test + void testGCD5() { + assertEquals(4, GcdLcm.getGCD(14159572, 63967072)); + } + + @Test + void testGCD6() { + assertEquals(4, GcdLcm.getGCD(63967072,14159572)); + } + + @Test + void testLCM1() { + assertEquals(24, GcdLcm.getLCM(6,8)); + } + + @Test + void testLCM2() { + assertEquals(1933053046, GcdLcm.getLCM(28851538, 1183019)); + } + + @Test + void testLCM3() { + assertEquals(226436590403296L, GcdLcm.getLCM(14159572, 63967072)); + } +} |