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[LeetCode] 1481. Least Number of Unique Integers after K Removals

Given an array of integers arr and an integer k. Find the least number of unique integers after removing exactly k elements. Example 1:Input: arr = [5,5,4], k = 1Output: 1Explanation: Remove

2021-03-12

#leetcode #array #hashmap #java #greedy #sort #heap

[LeetCode] 1151. Minimum Swaps to Group All 1s Together

Given a binary array data, return the minimum number of swaps required to group all 1’s present in the array together in any place in the array. Example 1:Input: data = [1,0,1,0,1]Output: 1Explan

2021-03-11

#leetcode #array #java #sliding window #sliding window with fixed size #prefix sum

[LeetCode] 1717. Maximum Score From Removing Substrings

You are given a string s and two integers x and y. You can perform two types of operations any number of times. Remove substring “ab” and gain x points.For example, when removing “ab” from “cabxbae” i

2021-03-04

#leetcode #java #greedy #string #stack

[LeetCode] 304. Range Sum Query 2D - Immutable

Given a 2D matrix matrix, handle multiple queries of the following type: Calculate the sum of the elements of matrix inside the rectangle defined by its upper left corner (row1, col1) and lower right

2021-03-02

#leetcode #java #prefix sum #matrix

[LeetCode] 303. Range Sum Query - Immutable

Given an integer array nums, handle multiple queries of the following type:Calculate the sum of the elements of nums between indices left and right inclusive where left <= right. Implement the

2021-03-01

#leetcode #java #prefix sum #design

[LeetCode] 1561. Maximum Number of Coins You Can Get

There are 3n piles of coins of varying size, you and your friends will take piles of coins as follows:In each step, you will choose any 3 piles of coins (not necessarily consecutive).Of your choice, A

2021-02-25

#leetcode #array #two pointer #greedy #sort

[LeetCode] 1052. Grumpy Bookstore Owner

Today, the bookstore owner has a store open for customers.length minutes. Every minute, some number of customers (customers[i]) enter the store, and all those customers leave after the end of that mi

2021-02-24

#leetcode #array #two pointer #java #sliding window #sliding window with fixed size

[LeetCode] 765. Couples Holding Hands

There are n couples sitting in 2n seats arranged in a row and want to hold hands. The people and seats are represented by an integer array row where row[i] is the ID of the person sitting in the ith s

2021-02-14

#leetcode #java #greedy #graph #union find

[LeetCode] 1208. Get Equal Substrings Within Budget

You are given two strings s and t of the same length and an integer maxCost. You want to change s to t. Changing the ith character of s to ith character of t costs |s[i] - t[i]| (i.e., the absolute di

2021-02-10

#leetcode #array #two pointer #java #sliding window

[LeetCode] 1423. Maximum Points You Can Obtain from Cards

There are several cards arranged in a row, and each card has an associated number of points. The points are given in the integer array cardPoints. In one step, you can take one card from the beginning

2021-02-06

#leetcode #array #java #sliding window #prefix sum