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anishLearnsToCodeanishLearnsToCode
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solves large number and repeated dna sequences in java
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‎README.md

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@@ -153,8 +153,8 @@
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| 171 | [Excel Sheet Column Number](https://leetcode.com/problems/excel-sheet-column-number) | [![Java](assets/java.png)](src/ExcelSheetColumnNumber.java) [![Python](assets/python.png)](python/excel_sheet_column_number.py) | |
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| 172 | [Factoring Trailing Zeroes](https://leetcode.com/problems/factorial-trailing-zeroes) | [![Java](assets/java.png)](src/FactorialTrailingZeros.java) [![Python](assets/python.png)](python/factorial_trailing_zeroes.py) | |
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| 173 | [Binary Search Tree Iterator](https://leetcode.com/problems/binary-search-tree-iterator) | [![Java](assets/java.png)](src/BinarySearchTreeIterator.java) | |
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| 179 | [Largest Number](https://leetcode.com/problems/largest-number) | | |
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| 187 | [Repeated DNA Sequences](https://leetcode.com/problems/repeated-dna-sequences) | | |
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| 179 | [Largest Number](https://leetcode.com/problems/largest-number) | [![Java](assets/java.png)](src/LargestNumber.java) | |
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| 187 | [Repeated DNA Sequences](https://leetcode.com/problems/repeated-dna-sequences) | [![Java](assets/java.png)](src/RepeatedDNASequences.java) | |
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| 189 | [Rotate Array](https://leetcode.com/problems/rotate-array) | [![Java](assets/java.png)](src/RotateArray.java) [![Python](assets/python.png)](python/rotate_array.py) | |
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| 190 | [Reverse Bits](https://leetcode.com/problems/reverse-bits) | [![Java](assets/java.png)](src/ReverseBits.java) [![Python](assets/python.png)](python/reverse_bits.py) | |
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| 191 | [Number of One Bits](https://leetcode.com/problems/number-of-1-bits) | [![Java](assets/java.png)](src/NumberOf1Bit.java) [![Python](assets/python.png)](python/number_of_1_bits.py) | |

‎src/HelloWorld.java

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@@ -1,16 +1,35 @@
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public class HelloWorld {
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public static void main(String[] args) {
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TreeNode root = new TreeNode(7);
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root.left = new TreeNode(3);
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root.right = new TreeNode(15);
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root.right.left = new TreeNode(9);
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root.right.right = new TreeNode(20);
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System.out.println(
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LargestNumber.largestNumber(new int[] {1, 2, 3})
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);
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TreePrinter.print(root);
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System.out.println(
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LargestNumber.largestNumber(new int[] {1, 2, 3, 4, 5, 6, 7, 8, 9})
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);
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BinarySearchTreeIterator.BSTIterator iterator = new BinarySearchTreeIterator.BSTIterator(root);
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while (iterator.hasNext()) {
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System.out.println(iterator.next());
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}
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System.out.println(
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LargestNumber.largestNumber(new int[] {10, 2})
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);
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System.out.println(
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LargestNumber.largestNumber(new int[] {1})
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);
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System.out.println(
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LargestNumber.largestNumber(new int[] {1, 10, 11, 12})
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);
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System.out.println(
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LargestNumber.largestNumber(new int[] {1, 10, 11, 12, 16, 15, 14, 13, 19, 18, 17})
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);
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System.out.println(
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LargestNumber.largestNumber(new int[] {3, 30, 34, 5, 9})
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);
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System.out.println(
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LargestNumber.largestNumber(new int[] {432, 43243})
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);
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}
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}

‎src/LargestNumber.java

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// https://leetcode.com/problems/largest-number
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// T: O(Nlog(N))
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// S: O(N)
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import java.util.ArrayList;
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import java.util.List;
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public class LargestNumber {
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private static final String ZERO = "0";
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public static String largestNumber(int[] nums) {
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final List<String> numbers = convertToStrings(nums);
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numbers.sort((s1, s2) -> {
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final String order1 = s1 + s2;
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final String order2 = s2 + s1;
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return order2.compareTo(order1);
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});
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if (numbers.get(0).equals(ZERO)) return ZERO;
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return combineStrings(numbers);
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}
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private static String combineStrings(List<String> numbers) {
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final StringBuilder result = new StringBuilder();
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for (String string : numbers) {
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result.append(string);
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}
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return result.toString();
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}
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private static List<String> convertToStrings(int[] array) {
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final List<String> numbers = new ArrayList<>();
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for (int number : array) {
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numbers.add(String.valueOf(number));
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}
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return numbers;
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}
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}

‎src/RepeatedDNASequences.java

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// https://leetcode.com/problems/repeated-dna-sequences
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// T: O(N)
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// S: O(N)
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import java.util.ArrayList;
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import java.util.HashSet;
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import java.util.List;
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import java.util.Map;
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import java.util.Set;
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public class RepeatedDNASequences {
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private static final Map<Character, Integer> NUCLEOTIDES_TO_INT = Map.ofEntries(
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Map.entry('A', 0),
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Map.entry('C', 1),
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Map.entry('G', 2),
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Map.entry('T', 3)
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);
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public List<String> findRepeatedDnaSequences(String s) {
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final List<String> dnaSequences = new ArrayList<>();
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final Set<Integer> encodings = new HashSet<>();
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final Set<Integer> repeatedEncodings = new HashSet<>();
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for (int i = 0 ; i < s.length() - 9 ; i++) {
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final int encoding = getSequenceEncoding(s, i);
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if (!encodings.add(encoding) && repeatedEncodings.add(encoding)) {
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dnaSequences.add(s.substring(i, i + 10));
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}
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}
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return dnaSequences;
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}
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private int getSequenceEncoding(String s, int index) {
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int encoding = 0;
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for (int i = index ; i < index + 10 ; i++) {
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encoding <<= 2;
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encoding |= NUCLEOTIDES_TO_INT.get(s.charAt(i));
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}
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return encoding;
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}
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}

‎src/TreeNode.java

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@@ -4,6 +4,16 @@ public class TreeNode implements TreePrinter.PrintableNode {
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TreeNode right;
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TreeNode() {}
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public static final TreeNode EXAMPLE_1;
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static {
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EXAMPLE_1 = new TreeNode(7);
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EXAMPLE_1.left = new TreeNode(3);
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EXAMPLE_1.right = new TreeNode(15);
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EXAMPLE_1.right.left = new TreeNode(9);
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EXAMPLE_1.right.right = new TreeNode(20);
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}
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TreeNode(int val) {
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this.val = val;
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}

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