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Java 19717 Potential issue in "Maximum Subarray Problem in Java" article (#14541)

This commit is contained in:
anuragkumawat 2023-08-25 15:39:06 +05:30 committed by GitHub
parent ed17162e4d
commit 63033cd8cf
2 changed files with 20 additions and 9 deletions
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14
algorithms-modules/algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/maximumsubarray/KadaneAlgorithm.java
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@ -5,7 +5,7 @@ import org.slf4j.LoggerFactory;
public class KadaneAlgorithm { public class KadaneAlgorithm {
private Logger logger = LoggerFactory.getLogger(BruteForceAlgorithm.class.getName()); private Logger logger = LoggerFactory.getLogger(KadaneAlgorithm.class.getName());
public int maxSubArraySum(int[] arr) { public int maxSubArraySum(int[] arr) {
@ -14,15 +14,15 @@ public class KadaneAlgorithm {
int end = 0; int end = 0;
int maxSoFar = arr[0], maxEndingHere = arr[0]; int maxSoFar = arr[0], maxEndingHere = arr[0];
for (int i = 1; i < size; i++) { for (int i = 1; i < size; i++) {
maxEndingHere = maxEndingHere + arr[i];
if (arr[i] > maxEndingHere + arr[i]) { if (arr[i] > maxEndingHere) {
start = i;
maxEndingHere = arr[i]; maxEndingHere = arr[i];
} else { if (maxSoFar < maxEndingHere) {
maxEndingHere = maxEndingHere + arr[i]; start = i;
}
} }
if (maxSoFar < maxEndingHere) { if (maxSoFar < maxEndingHere) {
maxSoFar = maxEndingHere; maxSoFar = maxEndingHere;
end = i; end = i;

15
algorithms-modules/algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/maximumsubarray/KadaneAlgorithmUnitTest.java
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@ -7,7 +7,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
class KadaneAlgorithmUnitTest { class KadaneAlgorithmUnitTest {
@Test @Test
void givenArrayWithNegativeNumberWhenMaximumSubarrayThenReturns6() { void givenArrayWithNegativeNumberWhenMaximumSubarrayThenReturnsExpectedResult() {
//given //given
int[] arr = new int[] { -3, 1, -8, 4, -1, 2, 1, -5, 5 }; int[] arr = new int[] { -3, 1, -8, 4, -1, 2, 1, -5, 5 };
//when //when
@ -27,7 +27,7 @@ class KadaneAlgorithmUnitTest {
//then //then
assertEquals(-1, maxSum); assertEquals(-1, maxSum);
} }
@Test @Test
void givenArrayWithAllPosiitveNumbersWhenMaximumSubarrayThenReturnsExpectedResult() { void givenArrayWithAllPosiitveNumbersWhenMaximumSubarrayThenReturnsExpectedResult() {
//given //given
@ -39,4 +39,15 @@ class KadaneAlgorithmUnitTest {
assertEquals(10, maxSum); assertEquals(10, maxSum);
} }
@Test
void givenArrayToTestStartIndexWhenMaximumSubarrayThenReturnsExpectedResult() {
//given
int[] arr = new int[] { 1, 2, -1, 3, -6, -2 };
//when
KadaneAlgorithm algorithm = new KadaneAlgorithm();
int maxSum = algorithm.maxSubArraySum(arr);
//then
assertEquals(5, maxSum);
}
} }