Category: algorithm

Fundamental

This is section talks about some fundamentals of algorithm learning.

Leetcode 1 Solution

This article provides solution to leetcode question 1 (two-sum)

Leetcode 2 Solution

This article provides solution to leetcode question 2 (add-two-numbers)

Algorithm

This section talks about algorithm related topics.

Leetcode 3 Solution

This article provides solution to leetcode question 3 (longest-substring-without-repeating-characters)

Leetcode 4 Solution

This article provides solution to leetcode question 4 (median-of-two-sorted-arrays)

Leetcode 5 Solution

This article provides solution to leetcode question 5 (longest-palindromic-substring)

Leetcode 6 Solution

This article provides solution to leetcode question 6 (zigzag-conversion)

Leetcode 7 Solution

This article provides solution to leetcode question 7 (reverse-integer)

Leetcode 8 Solution

This article provides solution to leetcode question 8 (string-to-integer-atoi)

Leetcode 9 Solution

This article provides solution to leetcode question 9 (palindrome-number)

Leetcode 10 Solution

This article provides solution to leetcode question 10 (regular-expression-matching)

Leetcode 11 Solution

This article provides solution to leetcode question 11 (container-with-most-water)

Leetcode 12 Solution

This article provides solution to leetcode question 12 (integer-to-roman)

Leetcode 13 Solution

This article provides solution to leetcode question 13 (roman-to-integer)

Leetcode 14 Solution

This article provides solution to leetcode question 14 (longest-common-prefix)

Leetcode 15 Solution

This article provides solution to leetcode question 15 (3sum)

Leetcode 16 Solution

This article provides solution to leetcode question 16 (3sum-closest)

Leetcode 17 Solution

This article provides solution to leetcode question 17 (letter-combinations-of-a-phone-number)

Leetcode 18 Solution

This article provides solution to leetcode question 18 (4sum)

Leetcode 19 Solution

This article provides solution to leetcode question 19 (remove-nth-node-from-end-of-list)

Leetcode 20 Solution

This article provides solution to leetcode question 20 (valid-parentheses)

Leetcode 21 Solution

This article provides solution to leetcode question 21 (merge-two-sorted-lists)

Leetcode 22 Solution

This article provides solution to leetcode question 22 (generate-parentheses)

Leetcode 23 Solution

This article provides solution to leetcode question 23 (merge-k-sorted-lists)

Leetcode 24 Solution

This article provides solution to leetcode question 24 (swap-nodes-in-pairs)

Leetcode 25 Solution

This article provides solution to leetcode question 25 (reverse-nodes-in-k-group)

Leetcode 26 Solution

This article provides solution to leetcode question 26 (remove-duplicates-from-sorted-array)

Leetcode 27 Solution

This article provides solution to leetcode question 27 (remove-element)

Leetcode 29 Solution

This article provides solution to leetcode question 29 (divide-two-integers)

Leetcode 30 Solution

This article provides solution to leetcode question 30 (substring-with-concatenation-of-all-words)

Leetcode 31 Solution

This article provides solution to leetcode question 31 (next-permutation)

Leetcode 32 Solution

This article provides solution to leetcode question 32 (longest-valid-parentheses)

Leetcode 33 Solution

This article provides solution to leetcode question 33 (search-in-rotated-sorted-array)

Leetcode 34 Solution

This article provides solution to leetcode question 34 (find-first-and-last-position-of-element-in-sorted-array)

Leetcode 35 Solution

This article provides solution to leetcode question 35 (search-insert-position)

Leetcode 36 Solution

This article provides solution to leetcode question 36 (valid-sudoku)

Leetcode 37 Solution

This article provides solution to leetcode question 37 (sudoku-solver)

Leetcode 38 Solution

This article provides solution to leetcode question 38 (count-and-say)

Leetcode 39 Solution

This article provides solution to leetcode question 39 (combination-sum)

Leetcode 40 Solution

This article provides solution to leetcode question 40 (combination-sum-ii)

Leetcode 41 Solution

This article provides solution to leetcode question 41 (first-missing-positive)

Leetcode 42 Solution

This article provides solution to leetcode question 42 (trapping-rain-water)

Leetcode 43 Solution

This article provides solution to leetcode question 43 (multiply-strings)

Leetcode 44 Solution

This article provides solution to leetcode question 44 (wildcard-matching)

Leetcode 45 Solution

This article provides solution to leetcode question 45 (jump-game-ii)

Leetcode 46 Solution

This article provides solution to leetcode question 46 (permutations)

Leetcode 47 Solution

This article provides solution to leetcode question 47 (permutations-ii)

Leetcode 48 Solution

This article provides solution to leetcode question 48 (rotate-image)

Leetcode 49 Solution

This article provides solution to leetcode question 49 (group-anagrams)

Leetcode 50 Solution

This article provides solution to leetcode question 50 (powx-n)

Leetcode 51 Solution

This article provides solution to leetcode question 51 (n-queens)

Leetcode 52 Solution

This article provides solution to leetcode question 52 (n-queens-ii)

Leetcode 53 Solution

This article provides solution to leetcode question 53 (maximum-subarray)

Leetcode 54 Solution

This article provides solution to leetcode question 54 (spiral-matrix)

Leetcode 55 Solution

This article provides solution to leetcode question 55 (jump-game)

Leetcode 56 Solution

This article provides solution to leetcode question 56 (merge-intervals)

Leetcode 57 Solution

This article provides solution to leetcode question 57 (insert-interval)

Leetcode 58 Solution

This article provides solution to leetcode question 58 (length-of-last-word)

Leetcode 59 Solution

This article provides solution to leetcode question 59 (spiral-matrix-ii)

Leetcode 60 Solution

This article provides solution to leetcode question 60 (permutation-sequence)

Leetcode 61 Solution

This article provides solution to leetcode question 61 (rotate-list)

Leetcode 62 Solution

This article provides solution to leetcode question 62 (unique-paths)

Leetcode 63 Solution

This article provides solution to leetcode question 63 (unique-paths-ii)

Leetcode 64 Solution

This article provides solution to leetcode question 64 (minimum-path-sum)

Leetcode 65 Solution

This article provides solution to leetcode question 65 (valid-number)

Leetcode 66 Solution

This article provides solution to leetcode question 66 (plus-one)

Leetcode 67 Solution

This article provides solution to leetcode question 67 (add-binary)

Leetcode 68 Solution

This article provides solution to leetcode question 68 (text-justification)

Leetcode 69 Solution

This article provides solution to leetcode question 69 (sqrtx)

Leetcode 70 Solution

This article provides solution to leetcode question 70 (climbing-stairs)

Leetcode 71 Solution

This article provides solution to leetcode question 71 (simplify-path)

Leetcode 72 Solution

This article provides solution to leetcode question 72 (edit-distance)

Leetcode 73 Solution

This article provides solution to leetcode question 73 (set-matrix-zeroes)

Leetcode 74 Solution

This article provides solution to leetcode question 74 (search-a-2d-matrix)

Leetcode 75 Solution

This article provides solution to leetcode question 75 (sort-colors)

Leetcode 76 Solution

This article provides solution to leetcode question 76 (minimum-window-substring)

Leetcode 77 Solution

This article provides solution to leetcode question 77 (combinations)

Leetcode 78 Solution

This article provides solution to leetcode question 78 (subsets)

Leetcode 79 Solution

This article provides solution to leetcode question 79 (word-search)

Leetcode 80 Solution

This article provides solution to leetcode question 80 (remove-duplicates-from-sorted-array-ii)

Leetcode 81 Solution

This article provides solution to leetcode question 81 (search-in-rotated-sorted-array-ii)

Leetcode 82 Solution

This article provides solution to leetcode question 82 (remove-duplicates-from-sorted-list-ii)

Leetcode 83 Solution

This article provides solution to leetcode question 83 (remove-duplicates-from-sorted-list)

Leetcode 84 Solution

This article provides solution to leetcode question 84 (largest-rectangle-in-histogram)

Leetcode 85 Solution

This article provides solution to leetcode question 85 (maximal-rectangle)

Leetcode 86 Solution

This article provides solution to leetcode question 86 (partition-list)

Leetcode 87 Solution

This article provides solution to leetcode question 87 (scramble-string)

Leetcode 88 Solution

This article provides solution to leetcode question 88 (merge-sorted-array)

Leetcode 89 Solution

This article provides solution to leetcode question 89 (gray-code)

Leetcode 90 Solution

This article provides solution to leetcode question 90 (subsets-ii)

Leetcode 91 Solution

This article provides solution to leetcode question 91 (decode-ways)

Leetcode 92 Solution

This article provides solution to leetcode question 92 (reverse-linked-list-ii)

Leetcode 93 Solution

This article provides solution to leetcode question 93 (restore-ip-addresses)

Leetcode 94 Solution

This article provides solution to leetcode question 94 (binary-tree-inorder-traversal)

Leetcode 95 Solution

This article provides solution to leetcode question 95 (unique-binary-search-trees-ii)

Leetcode 96 Solution

This article provides solution to leetcode question 96 (unique-binary-search-trees)

Leetcode 97 Solution

This article provides solution to leetcode question 97 (interleaving-string)

Leetcode 98 Solution

This article provides solution to leetcode question 98 (validate-binary-search-tree)

Leetcode 99 Solution

This article provides solution to leetcode question 99 (recover-binary-search-tree)

Leetcode 100 Solution

This article provides solution to leetcode question 100 (same-tree)

Leetcode 101 Solution

This article provides solution to leetcode question 101 (symmetric-tree)

Leetcode 102 Solution

This article provides solution to leetcode question 102 (binary-tree-level-order-traversal)

Leetcode 103 Solution

This article provides solution to leetcode question 103 (binary-tree-zigzag-level-order-traversal)

Leetcode 104 Solution

This article provides solution to leetcode question 104 (maximum-depth-of-binary-tree)

Leetcode 105 Solution

This article provides solution to leetcode question 105 (construct-binary-tree-from-preorder-and-inorder-traversal)

Leetcode 106 Solution

This article provides solution to leetcode question 106 (construct-binary-tree-from-inorder-and-postorder-traversal)

Leetcode 107 Solution

This article provides solution to leetcode question 107 (binary-tree-level-order-traversal-ii)

Leetcode 108 Solution

This article provides solution to leetcode question 108 (convert-sorted-array-to-binary-search-tree)

Leetcode 109 Solution

This article provides solution to leetcode question 109 (convert-sorted-list-to-binary-search-tree)

Leetcode 110 Solution

This article provides solution to leetcode question 110 (balanced-binary-tree)

Leetcode 111 Solution

This article provides solution to leetcode question 111 (minimum-depth-of-binary-tree)

Leetcode 112 Solution

This article provides solution to leetcode question 112 (path-sum)

Leetcode 113 Solution

This article provides solution to leetcode question 113 (path-sum-ii)

Leetcode 114 Solution

This article provides solution to leetcode question 114 (flatten-binary-tree-to-linked-list)

Leetcode 115 Solution

This article provides solution to leetcode question 115 (distinct-subsequences)

Leetcode 116 Solution

This article provides solution to leetcode question 116 (populating-next-right-pointers-in-each-node)

Leetcode 117 Solution

This article provides solution to leetcode question 117 (populating-next-right-pointers-in-each-node-ii)

Leetcode 118 Solution

This article provides solution to leetcode question 118 (pascals-triangle)

Leetcode 119 Solution

This article provides solution to leetcode question 119 (pascals-triangle-ii)

Leetcode 120 Solution

This article provides solution to leetcode question 120 (triangle)

Leetcode 121 Solution

This article provides solution to leetcode question 121 (best-time-to-buy-and-sell-stock)

Leetcode 122 Solution

This article provides solution to leetcode question 122 (best-time-to-buy-and-sell-stock-ii)

Leetcode 123 Solution

This article provides solution to leetcode question 123 (best-time-to-buy-and-sell-stock-iii)

Leetcode 124 Solution

This article provides solution to leetcode question 124 (binary-tree-maximum-path-sum)

Leetcode 125 Solution

This article provides solution to leetcode question 125 (valid-palindrome)

Leetcode 126 Solution

This article provides solution to leetcode question 126 (word-ladder-ii)

Leetcode 127 Solution

This article provides solution to leetcode question 127 (word-ladder)

Leetcode 128 Solution

This article provides solution to leetcode question 128 (longest-consecutive-sequence)

Leetcode 129 Solution

This article provides solution to leetcode question 129 (sum-root-to-leaf-numbers)

Leetcode 130 Solution

This article provides solution to leetcode question 130 (surrounded-regions)

Leetcode 131 Solution

This article provides solution to leetcode question 131 (palindrome-partitioning)

Leetcode 132 Solution

This article provides solution to leetcode question 132 (palindrome-partitioning-ii)

Leetcode 133 Solution

This article provides solution to leetcode question 133 (clone-graph)

Leetcode 134 Solution

This article provides solution to leetcode question 134 (gas-station)

Leetcode 135 Solution

This article provides solution to leetcode question 135 (candy)

Leetcode 136 Solution

This article provides solution to leetcode question 136 (single-number)

Leetcode 137 Solution

This article provides solution to leetcode question 137 (single-number-ii)

Leetcode 138 Solution

This article provides solution to leetcode question 138 (copy-list-with-random-pointer)

Leetcode 139 Solution

This article provides solution to leetcode question 139 (word-break)

Leetcode 140 Solution

This article provides solution to leetcode question 140 (word-break-ii)

Leetcode 141 Solution

This article provides solution to leetcode question 141 (linked-list-cycle)

Leetcode 142 Solution

This article provides solution to leetcode question 142 (linked-list-cycle-ii)

Leetcode 143 Solution

This article provides solution to leetcode question 143 (reorder-list)

Leetcode 144 Solution

This article provides solution to leetcode question 144 (binary-tree-preorder-traversal)

Leetcode 145 Solution

This article provides solution to leetcode question 145 (binary-tree-postorder-traversal)

Leetcode 146 Solution

This article provides solution to leetcode question 146 (lru-cache)

Leetcode 147 Solution

This article provides solution to leetcode question 147 (insertion-sort-list)

Leetcode 148 Solution

This article provides solution to leetcode question 148 (sort-list)

Leetcode 149 Solution

This article provides solution to leetcode question 149 (max-points-on-a-line)

Leetcode 150 Solution

This article provides solution to leetcode question 150 (evaluate-reverse-polish-notation)

Leetcode 151 Solution

This article provides solution to leetcode question 151 (reverse-words-in-a-string)

Leetcode 152 Solution

This article provides solution to leetcode question 152 (maximum-product-subarray)

Leetcode 153 Solution

This article provides solution to leetcode question 153 (find-minimum-in-rotated-sorted-array)

Leetcode 154 Solution

This article provides solution to leetcode question 154 (find-minimum-in-rotated-sorted-array-ii)

Leetcode 155 Solution

This article provides solution to leetcode question 155 (min-stack)

Leetcode 156 Solution

This article provides solution to leetcode question 156 (binary-tree-upside-down)

Leetcode 157 Solution

This article provides solution to leetcode question 157 (read-n-characters-given-read4)

Leetcode 158 Solution

This article provides solution to leetcode question 158 (read-n-characters-given-read4-ii-call-multiple-times)

Leetcode 159 Solution

This article provides solution to leetcode question 159 (longest-substring-with-at-most-two-distinct-characters)

Leetcode 160 Solution

This article provides solution to leetcode question 160 (intersection-of-two-linked-lists)

Leetcode 161 Solution

This article provides solution to leetcode question 161 (one-edit-distance)

Leetcode 162 Solution

This article provides solution to leetcode question 162 (find-peak-element)

Leetcode 163 Solution

This article provides solution to leetcode question 163 (missing-ranges)

Leetcode 164 Solution

This article provides solution to leetcode question 164 (maximum-gap)

Leetcode 165 Solution

This article provides solution to leetcode question 165 (compare-version-numbers)

Leetcode 166 Solution

This article provides solution to leetcode question 166 (fraction-to-recurring-decimal)

Leetcode 167 Solution

This article provides solution to leetcode question 167 (two-sum-ii-input-array-is-sorted)

Leetcode 168 Solution

This article provides solution to leetcode question 168 (excel-sheet-column-title)

Leetcode 169 Solution

This article provides solution to leetcode question 169 (majority-element)

Leetcode 170 Solution

This article provides solution to leetcode question 170 (two-sum-iii-data-structure-design)

Leetcode 171 Solution

This article provides solution to leetcode question 171 (excel-sheet-column-number)

Leetcode 172 Solution

This article provides solution to leetcode question 172 (factorial-trailing-zeroes)

Leetcode 173 Solution

This article provides solution to leetcode question 173 (binary-search-tree-iterator)

Leetcode 174 Solution

This article provides solution to leetcode question 174 (dungeon-game)

Leetcode 179 Solution

This article provides solution to leetcode question 179 (largest-number)

Leetcode 186 Solution

This article provides solution to leetcode question 186 (reverse-words-in-a-string-ii)

Leetcode 187 Solution

This article provides solution to leetcode question 187 (repeated-dna-sequences)

Leetcode 188 Solution

This article provides solution to leetcode question 188 (best-time-to-buy-and-sell-stock-iv)

Leetcode 189 Solution

This article provides solution to leetcode question 189 (rotate-array)

Leetcode 190 Solution

This article provides solution to leetcode question 190 (reverse-bits)

Leetcode 191 Solution

This article provides solution to leetcode question 191 (number-of-1-bits)

Leetcode 198 Solution

This article provides solution to leetcode question 198 (house-robber)

Leetcode 199 Solution

This article provides solution to leetcode question 199 (binary-tree-right-side-view)

Leetcode 200 Solution

This article provides solution to leetcode question 200 (number-of-islands)

Leetcode 201 Solution

This article provides solution to leetcode question 201 (bitwise-and-of-numbers-range)

Leetcode 202 Solution

This article provides solution to leetcode question 202 (happy-number)

Leetcode 203 Solution

This article provides solution to leetcode question 203 (remove-linked-list-elements)

Leetcode 204 Solution

This article provides solution to leetcode question 204 (count-primes)

Leetcode 205 Solution

This article provides solution to leetcode question 205 (isomorphic-strings)

Leetcode 206 Solution

This article provides solution to leetcode question 206 (reverse-linked-list)

Leetcode 207 Solution

This article provides solution to leetcode question 207 (course-schedule)

Leetcode 208 Solution

This article provides solution to leetcode question 208 (implement-trie-prefix-tree)

Leetcode 209 Solution

This article provides solution to leetcode question 209 (minimum-size-subarray-sum)

Leetcode 210 Solution

This article provides solution to leetcode question 210 (course-schedule-ii)

Leetcode 211 Solution

This article provides solution to leetcode question 211 (design-add-and-search-words-data-structure)

Leetcode 212 Solution

This article provides solution to leetcode question 212 (word-search-ii)

Leetcode 213 Solution

This article provides solution to leetcode question 213 (house-robber-ii)

Leetcode 214 Solution

This article provides solution to leetcode question 214 (shortest-palindrome)

Leetcode 215 Solution

This article provides solution to leetcode question 215 (kth-largest-element-in-an-array)

Leetcode 216 Solution

This article provides solution to leetcode question 216 (combination-sum-iii)

Leetcode 217 Solution

This article provides solution to leetcode question 217 (contains-duplicate)

Leetcode 218 Solution

This article provides solution to leetcode question 218 (the-skyline-problem)

Leetcode 219 Solution

This article provides solution to leetcode question 219 (contains-duplicate-ii)

Leetcode 220 Solution

This article provides solution to leetcode question 220 (contains-duplicate-iii)

Leetcode 221 Solution

This article provides solution to leetcode question 221 (maximal-square)

Leetcode 222 Solution

This article provides solution to leetcode question 222 (count-complete-tree-nodes)

Leetcode 223 Solution

This article provides solution to leetcode question 223 (rectangle-area)

Leetcode 224 Solution

This article provides solution to leetcode question 224 (basic-calculator)

Leetcode 225 Solution

This article provides solution to leetcode question 225 (implement-stack-using-queues)

Leetcode 226 Solution

This article provides solution to leetcode question 226 (invert-binary-tree)

Leetcode 227 Solution

This article provides solution to leetcode question 227 (basic-calculator-ii)

Leetcode 228 Solution

This article provides solution to leetcode question 228 (summary-ranges)

Leetcode 229 Solution

This article provides solution to leetcode question 229 (majority-element-ii)

Leetcode 230 Solution

This article provides solution to leetcode question 230 (kth-smallest-element-in-a-bst)

Leetcode 231 Solution

This article provides solution to leetcode question 231 (power-of-two)

Leetcode 232 Solution

This article provides solution to leetcode question 232 (implement-queue-using-stacks)

Leetcode 233 Solution

This article provides solution to leetcode question 233 (number-of-digit-one)

Leetcode 234 Solution

This article provides solution to leetcode question 234 (palindrome-linked-list)

Leetcode 235 Solution

This article provides solution to leetcode question 235 (lowest-common-ancestor-of-a-binary-search-tree)

Leetcode 236 Solution

This article provides solution to leetcode question 236 (lowest-common-ancestor-of-a-binary-tree)

Leetcode 237 Solution

This article provides solution to leetcode question 237 (delete-node-in-a-linked-list)

Leetcode 238 Solution

This article provides solution to leetcode question 238 (product-of-array-except-self)

Leetcode 239 Solution

This article provides solution to leetcode question 239 (sliding-window-maximum)

Leetcode 240 Solution

This article provides solution to leetcode question 240 (search-a-2d-matrix-ii)

Leetcode 241 Solution

This article provides solution to leetcode question 241 (different-ways-to-add-parentheses)

Leetcode 242 Solution