HackerRank - Number List

static int getNumberOfPrimes(int N) { int n = N+1;//to include 0 as the first number for easy index operations later final boolean a[] = new boolean[n]; //Initialized to null by default. Arrays.fill(a, true); a[0] = false; a[1] = false; for (int i =

1 if __name__ == '__main__': 2 n = int(input()) 3 arr = map(int, input().split()) 4 print(sorted(list(set(arr)))[-2])

题目链接:Median 做了整整一天T_T 尝试了各种方法: 首先看了解答,可以用multiset,但是发现java不支持: 然后想起来用堆,这个基本思想其实很巧妙的,就是维护一个最大堆和最小堆,最大堆存放前半部分较小的元素,最小堆存放后半部分较大的元素,并且最大堆的所有元素小于最小堆的所有元素:保持最大堆最多比最小堆多一个元素.每次插入元素的时候都先插入到最大堆,如果发现最大堆比最小堆多了两个个,那么就从最大堆里面拿出最大的放到最小堆里面:如果发现最大堆里面新插入的元素破坏了最大堆所有元素小于

题目连接:Game Of Rotation Mark is an undergraduate student and he is interested in rotation. A conveyor belt competition is going on in the town which Mark wants to win. In the competition, there's A conveyor belt which can be represented as a strip of 1

Classic and challenging DP! And you need combine several tricks together with DP to make it 100% pass. My main reference is here: https://github.com/havelessbemore/hackerrank/blob/master/algorithms/bit_manipulation/string-transmission.java Basically

Problem Statement You are given a matrix with m rows and n columns of cells, each of which contains either 1or 0. Two cells are said to be connected if they are adjacent to each other horizontally, vertically, or diagonally. The connected and filled

Little Bob loves chocolates, and goes to the store with $N money in his pocket. The price of each chocolate is $C. The store offers a discount: for every M wrappers he gives the store, he'll get one chocolate for free. How many chocolates does Bob ge

In the Quicksort challenges, you sorted an entire array. Sometimes, you just need specific information about a list of numbers, and doing a full sort would be unnecessary. Can you figure out a way to use your partition code to find the median in an a

One classic method for composing secret messages is called a square code.  The spaces are removed from the english text and the characters are written into a square (or rectangle). The width and height of the rectangle have the constraint, floor(sqrt