LeetCode

LeetCode 281 note: a queue of unfinished sources, take one value in turn and put the source back if anything remains; it generalizes to k sources

LeetCode 1059 note: trim outdegrees backward from the destination; a node is safe only when every outgoing edge leads to a safe node, and the destination itself must have no outgoing edges

LeetCode note for Decode Ways, rebuilt from the original learning note

LeetCode note for Word Break, rebuilt from the original learning note

LeetCode 3914 note: adding x to a range raises only the difference at its left edge by x, so the answer is the sum of all drops

LeetCode 3913 note: extract only the vowels, sort by (-count, first occurrence), and put them back into the vowel positions

LeetCode 3912 note: greater than all on the left means greater than the prefix maximum, and likewise for the right with the suffix maximum; scan both ways and output in original order

LeetCode 3910 note: n is tiny, so enumerate subsets with a bitmask, check the even sum first, then check that the induced subgraph is connected

LeetCode note for Alien Dictionary, rebuilt from the original learning note

LeetCode note for Cheapest Flights Within K Stops, rebuilt from the original learning note

LeetCode note for Min Cost Climbing Stairs, rebuilt from the original learning note

LeetCode note for Delete and Earn, rebuilt from the original learning note