Skip to content
Avio Lines
D2

Strings

104 stations · 38h

String manipulation, KMP, Z-algorithm, Rabin-Karp and palindromes. 104 interview problems explained by codestorywithMIK (38h of video), grouped into 7 patterns such as Frequency & Hashing, Two Pointers, Sliding Window.

Start this line →
problems by zone (pattern)
  • Frequency & Hashing28
  • Two Pointers15
  • Sliding Window13
  • Palindromes6
  • Pattern Matching (KMP / Z / Rabin-Karp)7
  • Parsing & Simulation13
  • String Building & Greedy39
  1. Frequency & Hashing

    0 of 28 passed
  2. EasyGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
  3. Count and SayLC 38 · 16:28
    MediumGoogle · Amazon · +10 more companiesLeetCode ↗ (opens in a new tab)
  4. MediumGoogle · Amazon · +5 more companiesLeetCode ↗ (opens in a new tab)
  5. Buddy StringsLC 859 · 15:42
    EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  6. Is SubsequenceLC 392 · 19:00
    MediumGoogle · Amazon · +5 more companiesLeetCode ↗ (opens in a new tab)
  7. MediumGoogle · Virtu FinancialLeetCode ↗ (opens in a new tab)
  8. MediumGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  9. MediumGoogle · Amazon · +8 more companiesLeetCode ↗ (opens in a new tab)
  10. Custom Sort StringLC 791 · 28:33
    MediumGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  11. Word SubsetsLC 916 · 27:48
    MediumGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
  12. HardGoogle · Meta · +1 more companiesLeetCode ↗ (opens in a new tab)
  13. MediumGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  14. MediumGoogle · Amazon · +1 more companiesLeetCode ↗ (opens in a new tab)
  15. Find the DifferenceLC 389 · 10:58
    EasyGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
  16. EasyGoogle · Amazon · +5 more companiesLeetCode ↗ (opens in a new tab)
  17. Valid AnagramLC 242 · 9:47
    EasyGoogle · Amazon · +37 more companiesLeetCode ↗ (opens in a new tab)
  18. EasyGoogle · Amazon · +21 more companiesLeetCode ↗ (opens in a new tab)
  19. EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  20. EasyGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
  21. EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  22. EasyGoogle · Amazon · +12 more companiesLeetCode ↗ (opens in a new tab)
  23. EasyGoogle · Meta · +2 more companiesLeetCode ↗ (opens in a new tab)
  24. Two Pointers

    0 of 15 passed
  25. EasyGoogle · Amazon · +14 more companiesLeetCode ↗ (opens in a new tab)
  26. EasyGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
  27. EasyGoogle · Amazon · +11 more companiesLeetCode ↗ (opens in a new tab)
  28. HardGoogle · Amazon · +5 more companiesLeetCode ↗ (opens in a new tab)
  29. Shortest PalindromeLC 214 · 36:39
    HardGoogle · Amazon · +6 more companiesLeetCode ↗ (opens in a new tab)
  30. Sentence Similarity IIILC 1813 · 25:40
    MediumGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
  31. MediumGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
  32. MediumGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  33. MediumGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  34. MediumGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
  35. Reverse Prefix of WordLC 2000 · 7:48
    EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  36. Longest PalindromeLC 409 · 19:16
    EasyGoogle · Amazon · +5 more companiesLeetCode ↗ (opens in a new tab)
  37. Sliding Window

    0 of 13 passed
  38. EasyGoogle · Amazon · +7 more companiesLeetCode ↗ (opens in a new tab)
  39. MediumGoogle · Virtu FinancialLeetCode ↗ (opens in a new tab)
  40. MediumAirbnb · Affirm · +1 more companiesLeetCode ↗ (opens in a new tab)
  41. MediumGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  42. MediumGoogle · Amazon · +1 more companiesLeetCode ↗ (opens in a new tab)
  43. EasyGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
  44. EasyGoogle · Amazon · +12 more companiesLeetCode ↗ (opens in a new tab)
  45. Palindromes

    0 of 6 passed
  46. MediumGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
  47. HardGoogle · Amazon · +5 more companiesLeetCode ↗ (opens in a new tab)
  48. Shortest PalindromeLC 214 · 36:39
    HardGoogle · Amazon · +6 more companiesLeetCode ↗ (opens in a new tab)
  49. MediumGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
  50. Longest PalindromeLC 409 · 19:16
    EasyGoogle · Amazon · +5 more companiesLeetCode ↗ (opens in a new tab)
  51. Pattern Matching (KMP / Z / Rabin-Karp)

    0 of 7 passed
  52. EasyGoogle · Amazon · +14 more companiesLeetCode ↗ (opens in a new tab)
  53. MediumGoogle · Microsoft · +1 more companiesLeetCode ↗ (opens in a new tab)
  54. Shortest PalindromeLC 214 · 36:39
    HardGoogle · Amazon · +6 more companiesLeetCode ↗ (opens in a new tab)
  55. Rotate StringLC 796 · 16:46
    EasyGoogle · Amazon · +10 more companiesLeetCode ↗ (opens in a new tab)
  56. EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  57. Parsing & Simulation

    0 of 13 passed
  58. String CompressionLC 443 · 19:34
    MediumGoogle · Amazon · +35 more companiesLeetCode ↗ (opens in a new tab)
  59. Text JustificationLC 68 · 35:17
    HardGoogle · Amazon · +33 more companiesLeetCode ↗ (opens in a new tab)
  60. EasyGoogle · Amazon · +11 more companiesLeetCode ↗ (opens in a new tab)
  61. MediumGoogle · Meta · +2 more companiesLeetCode ↗ (opens in a new tab)
  62. String Compression IIILC 3163 · 7:25
    MediumGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
  63. MediumGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  64. MediumGoogle · Amazon · +1 more companiesLeetCode ↗ (opens in a new tab)
  65. MediumGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
  66. HardGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
  67. EasyGoogle · Bloomberg · +1 more companiesLeetCode ↗ (opens in a new tab)
  68. EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  69. EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  70. String Building & Greedy

    0 of 39 passed
  71. MediumGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
  72. EasyGoogle · Amazon · +1 more companiesLeetCode ↗ (opens in a new tab)
  73. Make The String GreatLC 1544 · 12:23
    EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  74. EasyGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
  75. Restore IP AddressesLC 93 · 38:01
    MediumGoogle · Amazon · +17 more companiesLeetCode ↗ (opens in a new tab)
  76. Concatenated WordsLC 472 · 23:17
    HardAmazon · TikTokLeetCode ↗ (opens in a new tab)
  77. MediumGoogle · Amazon · +7 more companiesLeetCode ↗ (opens in a new tab)
  78. MediumAmazon · Meta · +3 more companiesLeetCode ↗ (opens in a new tab)
  79. Sort Vowels in a StringLC 2785 · 21:59
    MediumGoogle · Meta · +2 more companiesLeetCode ↗ (opens in a new tab)
  80. HardMicrosoft · Bloomberg · +1 more companiesLeetCode ↗ (opens in a new tab)
  81. MediumGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
  82. Maximum SwapLC 670 · 26:14
    MediumGoogle · Amazon · +6 more companiesLeetCode ↗ (opens in a new tab)
  83. MediumGoogle · Amazon · +6 more companiesLeetCode ↗ (opens in a new tab)
  84. MediumGoogle · Microsoft · +2 more companiesLeetCode ↗ (opens in a new tab)
  85. MediumGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
  86. MediumGoogle · Amazon · +1 more companiesLeetCode ↗ (opens in a new tab)
  87. MediumGoogle · Amazon · +1 more companiesLeetCode ↗ (opens in a new tab)
  88. MediumGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  89. HardGoogle · Amazon · +24 more companiesLeetCode ↗ (opens in a new tab)
  90. EasyGoogle · Meta · +3 more companiesLeetCode ↗ (opens in a new tab)
  91. EasyGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
  92. EasyGoogle · Amazon · +1 more companiesLeetCode ↗ (opens in a new tab)
  93. EasyAmazon · Meta · +4 more companiesLeetCode ↗ (opens in a new tab)
  94. EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
  95. EasyGoogle · Amazon · +5 more companiesLeetCode ↗ (opens in a new tab)
  96. Valid WordLC 3136 · 9:00
    EasyGoogle · Amazon · +6 more companiesLeetCode ↗ (opens in a new tab)
  97. EasyGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
  98. Length of Last WordLC 58 · 13:46
    EasyGoogle · Amazon · +5 more companiesLeetCode ↗ (opens in a new tab)

All 104 stations in order

  1. 1.Knuth-Morris-Pratt KMP String Matching Algorithm
  2. 2.Words Within Two Edits of Dictionary (LeetCode 2452)
  3. 3.String Compression (LeetCode 443)
  4. 4.Check if the Sentence Is Pangram (LeetCode 1832)
  5. 5.Count and Say (LeetCode 38)
  6. 6.Integer to Roman -(Amazon, Facebook, Microsoft, Twitter, Apple, Google..): Explanation ➕ Live Coding (LeetCode 12)
  7. 7.Check If Two String Arrays are Equivalent (LeetCode 1662)
  8. 8.Orderly Queue -(Amazon): Explanation ➕ Live Coding (LeetCode 899)
  9. 9.Make The String Great (LeetCode 1544)
  10. 10.Determine if String Halves Are Alike (LeetCode 1704)
  11. 11.Determine if Two Strings Are Close (LeetCode 1657)
  12. 12.Detect Capital -(GOOGLE) : Explanation ➕ Live Coding 🧑🏻‍💻👩🏻‍💻 (LeetCode 520)
  13. 13.Delete Columns to Make Sorted (LeetCode 944)
  14. 14.Restore IP Addresses (LeetCode 93)
  15. 15.Concatenated Words (LeetCode 472)
  16. 16.Find the Index of the First Occurrence in a String (LeetCode 28)
  17. 17.Buddy Strings (LeetCode 859)
  18. 18.Substring With Largest Variance (LeetCode 2272)
  19. 19.Repeated Substring Pattern (LeetCode 459)
  20. 20.Text Justification (LeetCode 68)
  21. 21.Is Subsequence (LeetCode 392)
  22. 22.Remove Duplicate Letters (LeetCode 316)
  23. 23.Decoded String at Index (LeetCode 880)
  24. 24.Reverse Words in a String III (LeetCode 557)
  25. 25.Backspace String Compare (LeetCode 844)
  26. 26.Count Number of Homogenous Substrings (LeetCode 1759)
  27. 27.Sort Vowels in a String (LeetCode 2785)
  28. 28.Unique Length-3 Palindromic Subsequences (LeetCode 1930)
  29. 29.Find Unique Binary String (LeetCode 1980)
  30. 30.Count Beautiful Substrings I (LeetCode 2947)
  31. 31.Count Beautiful Substrings II (LeetCode 2949)
  32. 32.Number of Ways to Divide a Long Corridor (LeetCode 2147)
  33. 33.Number of Laser Beams in a Bank (LeetCode 2125)
  34. 34.Minimum Number of Steps to Make Two Strings Anagram (LeetCode 1347)
  35. 35.Find Beautiful Indices in the Given Array (LeetCode 3006)
  36. 36.Minimum Time to Revert Word to Initial State (LeetCode 3029)
  37. 37.Custom Sort String (LeetCode 791)
  38. 38.Shortest Uncommon Substring in an Array (LeetCode 3076)
  39. 39.Count Substrings Starting and Ending with Given Character (LeetCode 3084)
  40. 40.Leetcode 165: Compare Version Numbers with stringstream (LeetCode 165)
  41. 41.Append Characters to String to Make Subsequence (LeetCode 2486)
  42. 42.Sort the Jumbled Numbers (LeetCode 2191)
  43. 43.Fraction Addition and Subtraction (LeetCode 592)
  44. 44.Find the Closest Palindrome (LeetCode 564)
  45. 45.Shortest Palindrome (LeetCode 214)
  46. 46.Sentence Similarity III (LeetCode 1813)
  47. 47.Separate Black and White Balls (LeetCode 2938)
  48. 48.Maximum Swap (LeetCode 670)
  49. 49.Remove Sub-Folders from the Filesystem (LeetCode 1233)
  50. 50.String Compression III (LeetCode 3163)
  51. 51.Minimum Number of Changes to Make Binary String Beautiful (LeetCode 2914)
  52. 52.Adding Spaces to a String (LeetCode 2109)
  53. 53.Make String a Subsequence Using Cyclic Increments (LeetCode 2825)
  54. 54.Move Pieces to Obtain a String (LeetCode 2337)
  55. 55.Find Longest Special Substring That Occurs Thrice I & II (LeetCode 2981)
  56. 56.Construct String With Repeat Limit (LeetCode 2182)
  57. 57.Minimum Number of Operations to Move All Balls to Each Box (LeetCode 1769)
  58. 58.Word Subsets (LeetCode 916)
  59. 59.Construct K Palindrome Strings (LeetCode 1400)
  60. 60.Minimum Length of String After Operations (LeetCode 3223)
  61. 61.Construct Smallest Number From DI String (LeetCode 2375)
  62. 62.Count the Number of Powerful Integers (LeetCode 2999)
  63. 63.Find the Lexicographically Largest String From the Box I (LeetCode 3403)
  64. 64.Using a Robot to Print the Lexicographically Smallest String (LeetCode 2434)
  65. 65.Count the Number of Substrings With Dominant Ones (LeetCode 3234)
  66. 66.Number of Substrings With Only 1s (LeetCode 1513)
  67. 67.Count Collisions on a Road (LeetCode 2211)
  68. 68.Delete Columns to Make Sorted II (LeetCode 955)
  69. 69.Decode the Slanted Ciphertext (LeetCode 2075)
  70. 70.Process String with Special Operations I (LeetCode 3612)
  71. 71.Process String with Special Operations II (LeetCode 3614)
  72. 72.Maximize Active Section with Trade I (LeetCode 3499)
  73. 73.Longest Valid Parentheses (LeetCode 32)
  74. 74.Minimum Operations to Sort a String (LeetCode 3863)
  75. 75.Find the Difference (LeetCode 389)
  76. 76.Find Words That Can Be Formed by Characters (LeetCode 1160)
  77. 77.Largest 3-Same-Digit Number in String (LeetCode 2264)
  78. 78.Largest Odd Number in String (LeetCode 1903)
  79. 79.Valid Anagram (LeetCode 242)
  80. 80.Maximum Score After Splitting a String (LeetCode 1422)
  81. 81.Minimum Changes To Make Alternating Binary String (LeetCode 1758)
  82. 82.Largest Substring Between Two Equal Characters (LeetCode 1624)
  83. 83.First Unique Character in a String (LeetCode 387)
  84. 84.Reverse Prefix of Word (LeetCode 2000)
  85. 85.Longest Palindrome (LeetCode 409)
  86. 86.Minimum String Length After Removing Substrings (LeetCode 2696)
  87. 87.Delete Characters to Make Fancy String (LeetCode 1957)
  88. 88.Rotate String (LeetCode 796)
  89. 89.String Matching in an Array (LeetCode 1408)
  90. 90.Check if One String Swap Can Make Strings Equal (LeetCode 1790)
  91. 91.Divide a String Into Groups of Size k (LeetCode 2138)
  92. 92.Find the Original Typed String I (LeetCode 3330)
  93. 93.Find the K-th Character in String Game I (LeetCode 3304)
  94. 94.Valid Word (LeetCode 3136)
  95. 95.Maximum Number of Words You Can Type (LeetCode 1935)
  96. 96.Find Resultant Array After Removing Anagrams (LeetCode 2273)
  97. 97.Check If Digits Are Equal in String After Operations I (LeetCode 3461)
  98. 98.Count Binary Substrings (LeetCode 696)
  99. 99.Check if Binary String Has at Most One Segment of Ones (LeetCode 1784)
  100. 100.Robot Return to Origin (LeetCode 657)
  101. 101.Furthest Point From Origin (LeetCode 2833)
  102. 102.Remove Outermost Parentheses (LeetCode 1021)
  103. 103.Find First Palindromic String in the Array (LeetCode 2108)
  104. 104.Length of Last Word (LeetCode 58)