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authorHaidong Ji2018-08-19 15:28:15 -0500
committerHaidong Ji2018-08-19 15:28:15 -0500
commitb3a6f3bc47098c81bef2c7d16690a5801149dbd8 (patch)
tree6646dbeefa43ec4f8fcc05c47985c1496a8aea76
parente56fcf9023ba43919cae20393a2b85d89206271c (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.java33
-rw-r--r--AlgoDesignAndTechniqueEdxJava/tests/GcdLcmTest.java48
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));
+ }
+}