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chore: [LEETCODE 1513] Number of Substrings With Only 1s <> Solution #76

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Merged
benmak11 merged 1 commit into from
Nov 16, 2025
Merged

chore: [LEETCODE 1513] Number of Substrings With Only 1s <> Solution #76

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19 changes: 19 additions & 0 deletions src/main/java/problemset/a1513/NumberOfSubstringsWithOnlyOnes.java
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package problemset.a1513;

public class NumberOfSubstringsWithOnlyOnes {
final int MODULO = (int) 1e9 + 7;

public int numSub(String s) {
int res = 0, consecutiveOnes = 0;

for (char c : s.toCharArray()) {
if (c == '1')
consecutiveOnes++;
else
consecutiveOnes = 0;

res = (res + consecutiveOnes) % MODULO;
}
return res;
}
}
38 changes: 38 additions & 0 deletions src/test/java/problemset/a1513/NumberOfSubstringsWithOnlyOnesTest.java
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package problemset.a1513;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.*;

class NumberOfSubstringsWithOnlyOnesTest {
private NumberOfSubstringsWithOnlyOnes numSubstrings;

private String testcaseOne;
private String testcaseTwo;
private String testcaseThree;

@BeforeEach
void setUp() {
numSubstrings = new NumberOfSubstringsWithOnlyOnes();

testcaseOne = "0110111";
testcaseTwo = "101";
testcaseThree = "111111";
}

@Test
void test_numSub_testCaseOne() {
assertEquals(9, numSubstrings.numSub(testcaseOne));
}

@Test
void test_numSub_testCaseTwo() {
assertEquals(2, numSubstrings.numSub(testcaseTwo));
}

@Test
void test_numSub_testCaseThree() {
assertEquals(21, numSubstrings.numSub(testcaseThree));
}
}
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