LeetCode

LeetCode note for Interleaving String, rebuilt from the original learning note

LeetCode note for Edit Distance, rebuilt from the original learning note

LeetCode 3989 note: the kept columns form a subsequence constrained only between neighbors; an LIS-style DP with dp[j] = the longest valid sequence ending at column j

LeetCode 316 note: a monotonic stack with last positions; pop a larger top that appears again later, and skip letters already on the stack

LeetCode 726 note: tokenize into elements, numbers, and parentheses; handle parentheses with a stack, with a default multiplier of 1

LeetCode note for Longest Palindromic Subsequence, rebuilt from the original learning note

LeetCode note for Longest Common Subsequence, rebuilt from the original learning note

LeetCode 757 note: sort by right end (larger left end first on ties) and track only the two rightmost points; add the two right-end points when uncovered, or the right end when only one is covered

LeetCode 552 note: state machine DP with state “A used × trailing L run”, 6 states; each day’s P, A or L picks the next state

LeetCode 51 note: one queen per row, with three sets tracking occupied columns and both diagonals

LeetCode 488 note: with at most 16 balls on the board and 5 in hand, memoize DFS on the whole (board, hand) state, inserting only before a same-colored ball or between two equal balls

LeetCode 1402 note: sort and take dishes from most satisfying down; each new dish goes first and shifts the chosen ones one slot later, adding the current chosen sum, so keep going while that sum is positive