摘要：Nothing magic here. Just BFS, but - BFS from land is not a good idea - BFS from Buildings.Lesson learnt: reverse thinking helps!class Solution {public... 阅读全文

摘要：https://leetcode.com/discuss/75014/math-solutionLesson learnt: dig deeper! 阅读全文

摘要：Another O(n^2) solution using bit ops. We prune 1/2(expected) candidates at each bit check.#define MAX_BITS 1600typedef bitset CandMask;class Solution... 阅读全文

摘要：What a classic DP problem..https://leetcode.com/discuss/72216/share-some-analysis-and-explanations 阅读全文

摘要：A classic type of problem: multi-pointer marching algorithm. For each pointer of each prime, we need to remember where it is in the ugly sequence, so ... 阅读全文

摘要：Almost identical to LintCode "Count of Smaller Number before Self". Corner case needs to be taken care of.class Solution { ////////////////// //... 阅读全文

摘要：BFS + HashTableclass Solution { int maxl, minl; unordered_map> hm;public: vector> verticalOrder(TreeNode* root) { maxl = INT_MIN; ... 阅读全文