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leetcode-ruby

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Some solved problems from LeetCode on Ruby.

Links

Profile on LeetCode: fartem.

Solutions

Easy

Name	Link to LeetCode	Link to solution
1. Two Sum	Link	Link
9. Palindrome Number	Link	Link
13. Roman to Integer	Link	Link
14. Longest Common Prefix	Link	Link
20. Valid Parentheses	Link	Link
21. Merge Two Sorted Lists	Link	Link
26. Remove Duplicates from Sorted Array	Link	Link
27. Remove Element	Link	Link
28. Find the Index of the First Occurrence in a String	Link	Link
35. Search Insert Position	Link	Link
58. Length of Last Word	Link	Link
66. Plus One	Link	Link
67. Add Binary	Link	Link
69. Sqrt(x)	Link	Link
70. Climbing Stairs	Link	Link
83. Remove Duplicates from Sorted List	Link	Link
88. Merge Sorted Array	Link	Link
94. Binary Tree Inorder Traversal	Link	Link
100. Same Tree	Link	Link
101. Symmetric Tree	Link	Link
104. Maximum Depth of Binary Tree	Link	Link
108. Convert Sorted Array to Binary Search Tree	Link	Link
110. Balanced Binary Tree	Link	Link
111. Minimum Depth of Binary Tree	Link	Link
112. Path Sum	Link	Link
118. Pascal's Triangle	Link	Link
119. Pascal's Triangle II	Link	Link
121. Best Time to Buy and Sell Stock	Link	Link
125. Valid Palindrome	Link	Link
136. Single Number	Link	Link
141. Linked List Cycle	Link	Link
144. Binary Tree Preorder Traversal	Link	Link
145. Binary Tree Postorder Traversal	Link	Link
160. Intersection of Two Linked Lists	Link	Link
168. Excel Sheet Column Title	Link	Link
169. Majority Element	Link	Link
171. Excel Sheet Column Number	Link	Link
190. Reverse Bits	Link	Link
191. Number of 1 Bits	Link	Link
202. Happy Number	Link	Link
203. Remove Linked List Elements	Link	Link
205. Isomorphic Strings	Link	Link
206. Reverse Linked List	Link	Link
217. Contains Duplicate	Link	Link
219. Contains Duplicate II	Link	Link
225. Implement Stack using Queues	Link	Link
226. Invert Binary Tree	Link	Link
228. Summary Ranges	Link	Link
231. Power of Two	Link	Link
232. Implement Queue using Stacks	Link	Link
234. Palindrome Linked List	Link	Link
242. Valid Anagram	Link	Link
257. Binary Tree Paths	Link	Link
258. Add Digits	Link	Link
263. Ugly Number	Link	Link
268. Missing Number	Link	Link
278. First Bad Version	Link	Link
283. Move Zeroes	Link	Link
290. Word Pattern	Link	Link
292. Nim Game	Link	Link
303. Range Sum Query - Immutable	Link	Link
326. Power of Three	Link	Link
338. Counting Bits	Link	Link
342. Power of Four	Link	Link
344. Reverse String	Link	Link
345. Reverse Vowels of a String	Link	Link
349. Intersection of Two Arrays	Link	Link
350. Intersection of Two Arrays II	Link	Link
367. Valid Perfect Square	Link	Link
374. Guess Number Higher or Lower	Link	Link
383. Ransom Note	Link	Link
387. First Unique Character in a String	Link	Link
389. Find the Difference	Link	Link
392. Is Subsequence	Link	Link
404. Sum of Left Leaves	Link	Link
405. Convert a Number to Hexadecimal	Link	Link
409. Longest Palindrome	Link	Link
412. Fizz Buzz	Link	Link
414. Third Maximum Number	Link	Link
415. Add Strings	Link	Link
434. Number of Segments in a String	Link	Link
441. Arranging Coins	Link	Link
448. Find All Numbers Disappeared in an Array	Link	Link
455. Assign Cookies	Link	Link
459. Repeated Substring Pattern	Link	Link
461. Hamming Distance	Link	Link
463. Island Perimeter	Link	Link
476. Number Complement	Link	Link
482. License Key Formatting	Link	Link
485. Max Consecutive Ones	Link	Link
492. Construct the Rectangle	Link	Link
496. Next Greater Element I	Link	Link
500. Keyboard Row	Link	Link
501. Find Mode in Binary Search Tree	Link	Link
504. Base 7	Link	Link
506. Relative Ranks	Link	Link
507. Perfect Number	Link	Link
509. Fibonacci Number	Link	Link
520. Detect Capital	Link	Link
521. Longest Uncommon Subsequence I	Link	Link
530. Minimum Absolute Difference in BST	Link	Link
543. Diameter of Binary Tree	Link	Link
551. Student Attendance Record I	Link	Link
557. Reverse Words in a String III	Link	Link
559. Maximum Depth of N-ary Tree	Link	Link
561. Array Partition	Link	Link
563. Binary Tree Tilt	Link	Link
566. Reshape the Matrix	Link	Link
572. Subtree of Another Tree	Link	Link
589. N-ary Tree Preorder Traversal	Link	Link
590. N-ary Tree Postorder Traversal	Link	Link
594. Longest Harmonious Subsequence	Link	Link
599. Minimum Index Sum of Two Lists	Link	Link
606. Construct String from Binary Tree	Link	Link
617. Merge Two Binary Trees	Link	Link
628. Maximum Product of Three Numbers	Link	Link
637. Average of Levels in Binary Tree	Link	Link
643. Maximum Average Subarray I	Link	Link
645. Set Mismatch	Link	Link
653. Two Sum IV - Input is a BST	Link	Link
657. Robot Return to Origin	Link	Link
671. Second Minimum Node In a Binary Tree	Link	Link
674. Longest Continuous Increasing Subsequence	Link	Link
680. Valid Palindrome II	Link	Link
682. Baseball Game	Link	Link
693. Binary Number with Alternating Bits	Link	Link
700. Search in a Binary Search Tree	Link	Link
703. Kth Largest Element in a Stream	Link	Link
704. Binary Search	Link	Link
705. Design HashSet	Link	Link
706. Design HashMap	Link	Link
709. To Lower Case	Link	Link
717. 1-bit and 2-bit Characters	Link	Link
724. Find Pivot Index	Link	Link
728. Self Dividing Numbers	Link	Link
733. Flood Fill	Link	Link
744. Find Smallest Letter Greater Than Target	Link	Link
746. Min Cost Climbing Stairs	Link	Link
747. Largest Number At Least Twice of Others	Link	Link
762. Prime Number of Set Bits in Binary Representation	Link	Link
766. Toeplitz Matrix	Link	Link
771. Jewels and Stones	Link	Link
783. Minimum Distance Between BST Nodes	Link	Link
796. Rotate String	Link	Link
804. Unique Morse Code Words	Link	Link
806. Number of Lines To Write String	Link	Link
812. Largest Triangle Area	Link	Link
819. Most Common Word	Link	Link
821. Shortest Distance to a Character	Link	Link
830. Positions of Large Groups	Link	Link
832. Flipping an Image	Link	Link
844. Backspace String Compare	Link	Link
859. Buddy Strings	Link	Link
860. Lemonade Change	Link	Link
867. Transpose Matrix	Link	Link
868. Binary Gap	Link	Link
872. Leaf-Similar Trees	Link	Link
876. Middle of the Linked List	Link	Link
884. Uncommon Words from Two Sentences	Link	Link
896. Monotonic Array	Link	Link
897. Increasing Order Search Tree	Link	Link
905. Sort Array By Parity	Link	Link
908. Smallest Range I	Link	Link
917. Reverse Only Letters	Link	Link
922. Sort Array By Parity II	Link	Link
925. Long Pressed Name	Link	Link
929. Unique Email Addresses	Link	Link
933. Number of Recent Calls	Link	Link
938. Range Sum of BST	Link	Link
941. Valid Mountain Array	Link	Link
942. DI String Match	Link	Link
944. Delete Columns to Make Sorted	Link	Link
953. Verifying an Alien Dictionary	Link	Link
961. N-Repeated Element in Size 2N Array	Link	Link
965. Univalued Binary Tree	Link	Link
976. Largest Perimeter Triangle	Link	Link
977. Squares of a Sorted Array	Link	Link
989. Add to Array-Form of Integer	Link	Link
993. Cousins in Binary Tree	Link	Link
997. Find the Town Judge	Link	Link
1002. Find Common Characters	Link	Link
1005. Maximize Sum Of Array After K Negations	Link	Link
1009. Complement of Base 10 Integer	Link	Link
1018. Binary Prefix Divisible By 5	Link	Link
1021. Remove Outermost Parentheses	Link	Link
1022. Sum of Root To Leaf Binary Numbers	Link	Link
1025. Divisor Game	Link	Link
1046. Last Stone Weight	Link	Link
1047. Remove All Adjacent Duplicates In String	Link	Link
1051. Height Checker	Link	Link
1071. Greatest Common Divisor of Strings	Link	Link
1078. Occurrences After Bigram	Link	Link
1089. Duplicate Zeros	Link	Link
1103. Distribute Candies to People	Link	Link
1108. Defanging an IP Address	Link	Link
1137. N-th Tribonacci Number	Link	Link
1154. Day of the Year	Link	Link
1160. Find Words That Can Be Formed by Characters	Link	Link
1184. Distance Between Bus Stops	Link	Link
1185. Day of the Week	Link	Link
1189. Maximum Number of Balloons	Link	Link
1200. Minimum Absolute Difference	Link	Link
1207. Unique Number of Occurrences	Link	Link
1217. Minimum Cost to Move Chips to The Same Position	Link	Link
1221. Split a String in Balanced Strings	Link	Link
1232. Check If It Is a Straight Line	Link	Link
1252. Cells with Odd Values in a Matrix	Link	Link
1266. Minimum Time Visiting All Points	Link	Link
1275. Find Winner on a Tic Tac Toe Game	Link	Link
1281. Subtract the Product and Sum of Digits of an Integer	Link	Link
1287. Element Appearing More Than 25% In Sorted Array	Link	Link
1290. Convert Binary Number in a Linked List to Integer	Link	Link
1295. Find Numbers with Even Number of Digits	Link	Link
1299. Replace Elements with Greatest Element on Right Side	Link	Link
1304. Find N Unique Integers Sum up to Zero	Link	Link
1309. Decrypt String from Alphabet to Integer Mapping	Link	Link
1313. Decompress Run-Length Encoded List	Link	Link
1317. Convert Integer to the Sum of Two No-Zero Integers	Link	Link
1323. Maximum 69 Number	Link	Link
1332. Remove Palindromic Subsequences	Link	Link
1337. The K Weakest Rows in a Matrix	Link	Link
1342. Number of Steps to Reduce a Number to Zero	Link	Link
1346. Check If N and Its Double Exist	Link	Link
1351. Count Negative Numbers in a Sorted Matrix	Link	Link
1356. Sort Integers by The Number of 1 Bits	Link	Link
1360. Number of Days Between Two Dates	Link	Link
1365. How Many Numbers Are Smaller Than the Current Number	Link	Link
1370. Increasing Decreasing String	Link	Link
1374. Generate a String With Characters That Have Odd Counts	Link	Link
1385. Find the Distance Value Between Two Arrays	Link	Link
1389. Create Target Array in the Given Order	Link	Link
1399. Count Largest Group	Link	Link
1403. Minimum Subsequence in Non-Increasing Order	Link	Link
1408. String Matching in an Array	Link	Link
1413. Minimum Value to Get Positive Step by Step Sum	Link	Link
1417. Reformat The String	Link	Link
1422. Maximum Score After Splitting a String	Link	Link
1431. Kids With the Greatest Number of Candies	Link	Link
1436. Destination City	Link	Link
1437. Check If All 1's Are at Least Length K Places Away	Link	Link
1446. Consecutive Characters	Link	Link
1450. Number of Students Doing Homework at a Given Time	Link	Link
1455. Check If a Word Occurs As a Prefix of Any Word in a Sentence	Link	Link
1460. Make Two Arrays Equal by Reversing Subarrays	Link	Link
1464. Maximum Product of Two Elements in an Array	Link	Link
1470. Shuffle the Array	Link	Link
1475. Final Prices With a Special Discount in a Shop	Link	Link
1480. Running Sum of 1d Array	Link	Link
1486. XOR Operation in an Array	Link	Link
1491. Average Salary Excluding the Minimum and Maximum Salary	Link	Link
1496. Path Crossing	Link	Link
1502. Can Make Arithmetic Progression From Sequence	Link	Link
1507. Reformat Date	Link	Link
1512. Number of Good Pairs	Link	Link
1518. Water Bottle	Link	Link
1523. Count Odd Numbers in an Interval Range	Link	Link
1528. Shuffle String	Link	Link
1534. Count Good Triplets	Link	Link
1539. Kth Missing Positive Number	Link	Link
1544. Make The String Great	Link	Link
1550. Three Consecutive Odds	Link	Link
1556. Thousand Separator	Link	Link
1566. Detect Pattern of Length M Repeated K or More Times	Link	Link
1572. Matrix Diagonal Sum	Link	Link
1576. Replace All ?'s to Avoid Consecutive Repeating Characters	Link	Link
1582. Special Positions in a Binary Matrix	Link	Link
1588. Sum of All Odd Length Subarrays	Link	Link
1592. Rearrange Spaces Between Words	Link	Link
1598. Crawler Log Folder	Link	Link
1603. Design Parking System	Link	Link
1608. Special Array With X Elements Greater Than or Equal X	Link	Link
1614. Maximum Nesting Depth of the Parentheses	Link	Link
1619. Mean of Array After Removing Some Elements	Link	Link
1624. Largest Substring Between Two Equal Characters	Link	Link
1629. Slowest Key	Link	Link
1636. Sort Array by Increasing Frequency	Link	Link
1646. Get Maximum in Generated Array	Link	Link
1652. Defuse the Bomb	Link	Link
1662. Check If Two String Arrays are Equivalent	Link	Link
1668. Maximum Repeating Substring	Link	Link
1672. Richest Customer Wealth	Link	Link
1678. Goal Parser Interpretation	Link	Link
1684. Count the Number of Consistent Strings	Link	Link
1688. Count of Matches in Tournament	Link	Link
1694. Reformat Phone Number	Link	Link
1700. Number of Students Unable to Eat Lunch	Link	Link
1704. Determine if String Halves Are Alike	Link	Link
1710. Maximum Units on a Truck	Link	Link
1716. Calculate Money in Leetcode Bank	Link	Link
1720. Decode XORed Array	Link	Link
1725. Number Of Rectangles That Can Form The Largest Square	Link	Link
1732. Find the Highest Altitude	Link	Link
1736. Latest Time by Replacing Hidden Digits	Link	Link
1748. Sum of Unique Elements	Link	Link
1752. Check if Array Is Sorted and Rotated	Link	Link
1768. Merge Strings Alternately	Link	Link
1773. Count Items Matching a Rule	Link	Link
1779. Find Nearest Point That Has the Same X or Y Coordinate	Link	Link
1784. Check if Binary String Has at Most One Segment of Ones	Link	Link
1790. Check if One String Swap Can Make Strings Equal	Link	Link
1791. Find Center of Star Graph	Link	Link
1796. Second Largest Digit in a String	Link	Link
1800. Maximum Ascending Subarray Sum	Link	Link
1805. Number of Different Integers in a String	Link	Link
1812. Determine Color of a Chessboard Square	Link	Link
1816. Truncate Sentence	Link	Link
1822. Sign of the Product of an Array	Link	Link
1827. Minimum Operations to Make the Array Increasing	Link	Link
1832. Check if the Sentence Is Pangram	Link	Link
1837. Sum of Digits in Base K	Link	Link
1844. Replace All Digits with Characters	Link	Link
1848. Minimum Distance to the Target Element	Link	Link
1859. Sorting the Sentence	Link	Link
1863. Sum of All Subset XOR Totals	Link	Link
1869. Longer Contiguous Segments of Ones than Zeros	Link	Link
1876. Substrings of Size Three with Distinct Characters	Link	Link
1880. Check if Word Equals Summation of Two Words	Link	Link
1886. Determine Whether Matrix Can Be Obtained By Rotation	Link	Link
1893. Check if All the Integers in a Range Are Covered	Link	Link
1897. Redistribute Characters to Make All Strings Equal	Link	Link
1903. Largest Odd Number in String	Link	Link
1909. Remove One Element to Make the Array Strictly Increasing	Link	Link
1913. Maximum Product Difference Between Two Pairs	Link	Link
1920. Build Array from Permutation	Link	Link
1925. Count Square Sum Triples	Link	Link
1929. Concatenation of Array	Link	Link
1935. Maximum Number of Words You Can Type	Link	Link
1941. Check if All Characters Have Equal Number of Occurrences	Link	Link
1952. Three Divisors	Link	Link
1957. Delete Characters to Make Fancy String	Link	Link
1961. Check If String Is a Prefix of Array	Link	Link
1967. Number of Strings That Appear as Substrings in Word	Link	Link
1971. Find if Path Exists in Graph	Link	Link
1974. Minimum Time to Type Word Using Special Typewriter	Link	Link
1979. Find Greatest Common Divisor of Array	Link	Link
1984. Minimum Difference Between Highest and Lowest of K Scores	Link	Link
1991. Find the Middle Index in Array	Link	Link
1995. Count Special Quadruplets	Link	Link
2000. Reverse Prefix of Word	Link	Link
2006. Count Number of Pairs With Absolute Difference K	Link	Link
2011. Final Value of Variable After Performing Operations	Link	Link
2016. Maximum Difference Between Increasing Elements	Link	Link
2022. Convert 1D Array Into 2D Array	Link	Link
2027. Minimum Moves to Convert String	Link	Link
2032. Two Out of Three	Link	Link
2037. Minimum Number of Moves to Seat Everyone	Link	Link
2042. Check if Numbers Are Ascending in a Sentence	Link	Link
2047. Number of Valid Words in a Sentence	Link	Link
2053. Kth Distinct String in an Array	Link	Link
2057. Smallest Index With Equal Value	Link	Link
2062. Count Vowel Substrings of a String	Link	Link
2068. Check Whether Two Strings are Almost Equivalent	Link	Link
2073. Time Needed to Buy Tickets	Link	Link
2078. Two Furthest Houses With Different Colors	Link	Link
2085. Count Common Words With One Occurrence	Link	Link
2089. Find Target Indices After Sorting Array	Link	Link
2094. Finding 3-Digit Even Numbers	Link	Link
2099. Find Subsequence of Length K With the Largest Sum	Link	Link
2103. Rings and Rods	Link	Link
2108. Find First Palindromic String in the Array	Link	Link
2114. Maximum Number of Words Found in Sentences	Link	Link
2119. A Number After a Double Reversal	Link	Link
2124. Check if All A's Appears Before All B's	Link	Link
2129. Capitalize the Title	Link	Link
2133. Check if Every Row and Column Contains All Numbers	Link	Link
2138. Divide a String Into Groups of Size k	Link	Link
2148. Count Elements With Strictly Smaller and Greater Elements	Link	Link
2154. Keep Multiplying Found Values by Two	Link	Link
2160. Minimum Sum of Four Digit Number After Splitting Digits	Link	Link
2164. Sort Even and Odd Indices Independently	Link	Link
2169. Count Operations to Obtain Zero	Link	Link
2176. Count Equal and Divisible Pairs in an Array	Link	Link
2180. Count Integers With Even Digit Sum	Link	Link
2185. Counting Words With a Given Prefix	Link	Link
2190. Most Frequent Number Following Key In an Array	Link	Link
2194. Cells in a Range on an Excel Sheet	Link	Link
2206. Divide Array Into Equal Pairs	Link	Link
2210. Count Hills and Valleys in an Array	Link	Link
2215. Find the Difference of Two Arrays	Link	Link
2220. Minimum Bit Flips to Convert Number	Link	Link
2231. Largest Number After Digit Swaps by Parity	Link	Link
2235. Add Two Integers	Link	Link
2236. Root Equals Sum of Children	Link	Link
2239. Find Closest Number to Zero	Link	Link
2243. Calculate Digit Sum of a String	Link	Link
2248. Intersection of Multiple Arrays	Link	Link
2255. Count Prefixes of a Given String	Link	Link
2259. Remove Digit From Number to Maximize Result	Link	Link
2264. Largest 3-Same-Digit Number in String	Link	Link