LeetCode 127. Word Ladder

The problem is to find the next word in the wordList.

LeetCode 1315. Sum of Nodes with Even-Valued Grandparent

So we can use the parent to represent grandparent.

LeetCode 621. Task Scheduler

Because the tasks have cooldown period, so we want the task with maximum occurrences do first.

LeetCode 2335. Minimum Amount of Time to Fill Cups

max(ceil(sum(A) / 2), max(A))

LeetCode 2231. Largest Number After Digit Swaps by Parity

This problem can be translated into...

LeetCode 1046. Last Stone Weight

Do as the game. Choose two heaviest stone and do the subtraction.

LeetCode 2099. Find Subsequence of Length K With the Largest Sum

Use priority queue to find the largest k numbers. also and their index.

LeetCode 703. Kth Largest Element in a Stream

Maintain a Heap that contains only the K biggest the element.

LeetCode 506. Relative Ranks

First we need to sort the scores from biggest to smallest.

LeetCode 218. The Skyline Problem

Calculate the building in lines not by the whole building.

开关灯&调整电平

找1~n中的完全平方数

2018 ACM-ICPC Asia Flippy Sequence ZOJ-4060