ABCDEFGHIJKLMNOPQRSTUVWXYZAA
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LinkCategoryNeed to reviewNote
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1https://leetcode.com/problems/powx-n/MathNo
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2https://leetcode.com/problems/valid-sudokuMathNo
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3https://leetcode.com/problems/sudoku-solverBacktrackingYesO((9!)^9)
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4https://leetcode.com/problems/intersection-of-three-sorted-arraysAdhocNo
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5https://leetcode.com/problems/stepping-numbersDFSYesO(9 * (2^10-1))
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6https://leetcode.com/problems/snapshot-array/TLSYesauto it = map.upper_bound(key);
it--;
return it->second;
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7https://leetcode.com/problems/my-calendar-iTLSYes
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8https://leetcode.com/problems/my-calendar-iirange queryYes
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9https://leetcode.com/problems/my-calendar-iiirange queryNo
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10https://leetcode.com/problems/meeting-rooms-iirange queryNo
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11https://leetcode.com/problems/meeting-schedulerTLSYes
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12https://leetcode.com/problems/remove-covered-intervalsGreedyNo
sort(a.begin(), a.end(), [](auto u, auto v) { });
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13https://leetcode.com/problems/remove-interval/AdhocNocomplicated if else
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14https://leetcode.com/problems/largest-divisible-subsetDPYesdp with tracing array
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15https://leetcode.com/problems/hand-of-straightsAdhoc, TLSNo
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16https://leetcode.com/problems/maximize-distance-to-closest-personAdhocNo
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17https://leetcode.com/problems/exam-roomTLSNoset.insert(p), set.erase(p)
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18https://leetcode.com/problems/the-k-weakest-rows-in-a-matrixBinary search, Adhoc, Constant memYes
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19https://leetcode.com/problems/minimum-increment-to-make-array-uniqueAdhocYeslazy update
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20https://leetcode.com/problems/convert-binary-search-tree-to-sorted-doubly-linked-listTreeYesComplex recursion
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21https://leetcode.com/problems/binary-tree-inorder-traversalTreeNoleft, print, right
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22https://leetcode.com/problems/binary-tree-preorder-traversalTreeNo
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23https://leetcode.com/problems/binary-tree-postorder-traversalTreeNo
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24https://leetcode.com/problems/closest-binary-search-tree-valueTreeYesO(h), binary search
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25https://leetcode.com/problems/binary-search-tree-iteratorBSTYesiterative
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26https://leetcode.com/problems/binary-tree-inorder-traversal/TreeYesiterative
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27https://leetcode.com/problems/validate-binary-search-treeBSTNonotice over flow
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28https://leetcode.com/problems/find-mode-in-binary-search-treeBSTNo
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29https://leetcode.com/problems/inorder-successor-in-bstBSTYes
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30https://leetcode.com/problems/inorder-successor-in-bst-iiBSTNo
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31https://leetcode.com/problems/maximum-width-of-binary-tree/TreeYes
number the node: u => u*2 - prevRight, u*2 + 1 - prevRight
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https://leetcode.com/problems/reorder-routes-to-make-all-paths-lead-to-the-city-zero/
DFSNo
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33https://leetcode.com/problems/reveal-cards-in-increasing-order/DequeNojust revert the process
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34https://leetcode.com/problems/binary-tree-vertical-order-traversalBFSNo
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35https://leetcode.com/problems/binary-tree-level-order-traversalBFSYeslevel travel
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36https://leetcode.com/problems/rotate-image/AdhocNo
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37https://leetcode.com/problems/remove-duplicates-from-sorted-arrayAdhocYes
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38https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii/AdhocNo
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39https://leetcode.com/problems/asteroid-collision/StackYes
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40https://leetcode.com/problems/can-place-flowersAdhocNo
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41https://leetcode.com/problems/minimum-size-subarray-sum2-pointersYesi = j = 0
init(fx, 0)
while (i < n) {
if (ok) {
update(res);
update(fx);
j++;
} else {
i++;
if (i < n) update(fx);
}
}
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42https://leetcode.com/problems/maximum-size-subarray-sum-equals-khashmapNomap.find(i) == map.end()
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43https://leetcode.com/problems/subarray-product-less-than-k2-pointersYes
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44https://leetcode.com/problems/maximum-length-of-repeated-subarraydpNoLCS
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https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal
tree constructionYes
- inOrder element splits inOrder list into 2 parts, each part is all node of a subtree
- first preOrder element is the root
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https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal
tree constructionYes
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47https://leetcode.com/problems/subsetsbit manipulationNo1 << n
(n >> i) & 1
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48https://leetcode.com/problems/subsets-ii/recursionYes
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49https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversaltree constructionYes
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50https://leetcode.com/problems/serialize-and-deserialize-bsttree constructionYes
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51https://leetcode.com/problems/max-area-of-islanddfsNo
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52https://leetcode.com/problems/island-perimeteradhocNo
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53https://leetcode.com/problems/coloring-a-borderdfsNo
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54https://leetcode.com/problems/missing-numberadhocNo
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55https://leetcode.com/problems/find-the-duplicate-numberConstant memYes
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56https://leetcode.com/problems/single-numberbit manipulationNo0 xor 1 = 1
1 xor 1 = 0
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57https://leetcode.com/problems/find-all-numbers-disappeared-in-an-arrayConstant memNo
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58https://leetcode.com/problems/find-all-duplicates-in-an-array/Constant memNo
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59https://leetcode.com/problems/first-missing-positiveConstant memYes
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60https://leetcode.com/problems/trapping-rain-wateradhocYes
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61https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/bfsNo
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62https://leetcode.com/problems/binary-tree-right-side-view/bfsNo
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63https://leetcode.com/problems/shortest-distance-from-all-buildingsbfsYesoptimized bfs, O(#1 * n * m)
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64https://leetcode.com/problems/best-meeting-pointmathNomedian point
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65https://leetcode.com/problems/as-far-from-land-as-possible/bfsNo
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66https://leetcode.com/problems/maximum-profit-in-job-schedulingdpYeswow
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67https://leetcode.com/problems/valid-perfect-squarebinary searchNo
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