JAVA problem

Task 5: More Complex Array Usage

public static boolean anyDuplicates(int[] xs)

Given an array of integers, if the same value occurs twice anywhere, return true; if not, return false.

reminder: Although Python used upper-case words (True and False), we're not writing Python! In Java, the boolean values are written all lowercase: true, false.

public static int largestAscent(int[] xs)

Given an array of integers, we can conceptually split it into separate non-decreasing sequences. Each sequence has a first and last item, and thus spans some range of values. Find the sequence that has the largest gap from its beginning low-point to its ending high-point, and return this distance.

Examples:

sequence	largest ascent	reasoning
1,2,3,4,2,10	8	(10-2) is greater than (4-1)
1,5,5,10,2,9	9	1,5,5,10 counts as one ascent.
5	0	degenerate case; (5-5)==0.

Manual Inspection Criteria(5%) Solve this one with a single loop (any kind).

Solutions go here:

public class Task5 { /* given an array of ints, are there any duplicates in the list? */ public static boolean anyDuplicates(int[] xs){ // delete this when you implement it. throw new RuntimeException("not implemented!"); return false; } /* given an array of ints, split into non-descending subsequences, * what is the largest difference from first to last? */ public static int largestAscent(int[] xs){ // delete this when you implement it. throw new RuntimeException("not implemented!"); } }

Tester:

import org.junit.*; import static org.junit.Assert.*; import java.util.*; public class Task5Tests { public static void main(String args[]){ org.junit.runner.JUnitCore.main("Task5Tests"); } @Test public void task5_anyDuplicates_01() { assertEquals( false, Task5.anyDuplicates( new int[]{} )); } @Test public void task5_anyDuplicates_02() { assertEquals( false, Task5.anyDuplicates( new int[]{5} )); } @Test public void task5_anyDuplicates_03() { assertEquals( false, Task5.anyDuplicates( new int[]{1,2,3,4} )); } @Test public void task5_anyDuplicates_04() { assertEquals( true , Task5.anyDuplicates( new int[]{3,4,5,6,7,4,8} )); } @Test public void task5_anyDuplicates_05() { assertEquals( true , Task5.anyDuplicates( new int[]{7,6,5,2,2} )); } @Test public void task5_anyDuplicates_06() { assertEquals( true , Task5.anyDuplicates( new int[]{1,1,1,1,1,1,1,1,1} )); } @Test public void task5_anyDuplicates_07() { assertEquals( false, Task5.anyDuplicates( new int[]{6,4} )); } @Test public void task5_anyDuplicates_08() { assertEquals( true , Task5.anyDuplicates( new int[]{1,2,3,2,0} )); } @Test public void task5_anyDuplicates_09() { assertEquals( false, Task5.anyDuplicates( new int[]{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20} )); } @Test public void task5_anyDuplicates_10() { assertEquals( true , Task5.anyDuplicates( new int[]{-1,-2,-3,-4,-5,-3,-2,-1} )); }

@Test public void task5_largestAscent_01() { assertEquals( 8, Task5.largestAscent( new int[]{1,2,3,4,2,10} )); } @Test public void task5_largestAscent_02() { assertEquals( 9, Task5.largestAscent( new int[]{1,5,5,10,2,9} )); } @Test public void task5_largestAscent_03() { assertEquals( 0, Task5.largestAscent( new int[]{5} )); } @Test public void task5_largestAscent_04() { assertEquals( 0, Task5.largestAscent( new int[]{5,4,3,2,1} )); } @Test public void task5_largestAscent_05() { assertEquals( 4, Task5.largestAscent( new int[]{1,2,2,3,4,5,4,5,6,7} )); } @Test public void task5_largestAscent_06() { assertEquals( 4050, Task5.largestAscent( new int[]{1,10,100,3000,450,4500} )); } @Test public void task5_largestAscent_07() { assertEquals( 8, Task5.largestAscent( new int[]{-10,-2,-3,1,0,5} )); } @Test public void task5_largestAscent_08() { assertEquals( 100, Task5.largestAscent( new int[]{-100,-50,-75,25,1,60} )); } @Test public void task5_largestAscent_09() { assertEquals( 500, Task5.largestAscent( new int[]{0,500} )); } @Test public void task5_largestAscent_10() { assertEquals( 0, Task5.largestAscent( new int[]{} )); }

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