iSharkFly-Docs
/
java-tutorials
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

create triangles with for loops - examples (#7513)

This commit is contained in:
Catalin Burcea 2019-08-10 18:05:51 +03:00 committed by KevinGilmore
parent 2a9050ef90
commit 7211b74b11
3 changed files with 155 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
algorithms-miscellaneous-3/pom.xml
View File

@ -30,6 +30,19 @@
<artifactId>guava</artifactId>
<version>${guava.version}</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.8.1</version>
</dependency>
<dependency>
<groupId>pl.pragmatists</groupId>
<artifactId>JUnitParams</artifactId>
<version>1.1.0</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>

49
algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/printtriangles/PrintTriangleExamples.java Normal file
View File

@ -0,0 +1,49 @@
package com.baeldung.algorithms.printtriangles;
import org.apache.commons.lang3.StringUtils;
public class PrintTriangleExamples {
public static String printARightAngledTriangle(int N) {
StringBuilder result = new StringBuilder();
for (int r = 1; r <= N; r++) {
for (int j = 1; j <= r; j++) {
result.append("*");
}
result.append(System.lineSeparator());
}
return result.toString();
}
public static String printAnIsoscelesTriangle(int N) {
StringBuilder result = new StringBuilder();
for (int r = 1; r <= N; r++) {
for (int sp = 1; sp <= N - r; sp++) {
result.append(" ");
}
for (int c = 1; c <= (r * 2) - 1; c++) {
result.append("*");
}
result.append(System.lineSeparator());
}
return result.toString();
}
public static String printAnIsoscelesTriangleUsingSubstring(int N) {
StringBuilder result = new StringBuilder();
String helperString = StringUtils.repeat(' ', N - 1) + StringUtils.repeat('*', N * 2 - 1);
for (int r = 0; r < N; r++) {
result.append(helperString.substring(r, N + 2 * r));
result.append(System.lineSeparator());
}
return result.toString();
}
public static void main(String[] args) {
System.out.println(printARightAngledTriangle(5));
System.out.println(printAnIsoscelesTriangle(5));
System.out.println(printAnIsoscelesTriangleUsingSubstring(5));
}
}

93
algorithms-miscellaneous-3/src/test/java/com/baeldung/algorithms/printtriangles/PrintTriangleExamplesUnitTest.java Normal file
View File

@ -0,0 +1,93 @@
package com.baeldung.algorithms.printtriangles;
import junitparams.JUnitParamsRunner;
import junitparams.Parameters;
import org.junit.Test;
import org.junit.runner.RunWith;
import static org.junit.Assert.assertEquals;
@RunWith(JUnitParamsRunner.class)
public class PrintTriangleExamplesUnitTest {
private static Object[][] rightAngledTriangles() {
String expected0 = "";
String expected2 = "*" + System.lineSeparator()
+ "**" + System.lineSeparator();
String expected5 = "*" + System.lineSeparator()
+ "**" + System.lineSeparator()
+ "***" + System.lineSeparator()
+ "****" + System.lineSeparator()
+ "*****" + System.lineSeparator();
String expected7 = "*" + System.lineSeparator()
+ "**" + System.lineSeparator()
+ "***" + System.lineSeparator()
+ "****" + System.lineSeparator()
+ "*****" + System.lineSeparator()
+ "******" + System.lineSeparator()
+ "*******" + System.lineSeparator();
return new Object[][] {
{ 0, expected0 },
{ 2, expected2 },
{ 5, expected5 },
{ 7, expected7 }
};
}
@Test
@Parameters(method = "rightAngledTriangles")
public void whenPrintARightAngledTriangleIsCalled_ThenTheCorrectStringIsReturned(int nrOfRows, String expected) {
String actual = PrintTriangleExamples.printARightAngledTriangle(nrOfRows);
assertEquals(expected, actual);
}
private static Object[][] isoscelesTriangles() {
String expected0 = "";
String expected2 = " *" + System.lineSeparator()
+ "***" + System.lineSeparator();
String expected5 = " *" + System.lineSeparator()
+ " ***" + System.lineSeparator()
+ " *****" + System.lineSeparator()
+ " *******" + System.lineSeparator()
+ "*********" + System.lineSeparator();
String expected7 = " *" + System.lineSeparator()
+ " ***" + System.lineSeparator()
+ " *****" + System.lineSeparator()
+ " *******" + System.lineSeparator()
+ " *********" + System.lineSeparator()
+ " ***********" + System.lineSeparator()
+ "*************" + System.lineSeparator();
return new Object[][] {
{ 0, expected0 },
{ 2, expected2 },
{ 5, expected5 },
{ 7, expected7 }
};
}
@Test
@Parameters(method = "isoscelesTriangles")
public void whenPrintAnIsoscelesTriangleIsCalled_ThenTheCorrectStringIsReturned(int nrOfRows, String expected) {
String actual = PrintTriangleExamples.printAnIsoscelesTriangle(nrOfRows);
assertEquals(expected, actual);
}
@Test
@Parameters(method = "isoscelesTriangles")
public void whenPrintAnIsoscelesTriangleUsingSubstringIsCalled_ThenTheCorrectStringIsReturned(int nrOfRows, String expected) {
String actual = PrintTriangleExamples.printAnIsoscelesTriangleUsingSubstring(nrOfRows);
assertEquals(expected, actual);
}
}