1779. Find Nearest Point That Has the Same X or Y Coordinate

2021-07-22

Problem description:

You are given two integers, x and y, which represent your current location on a Cartesian grid: (x, y). You are also given an array points where each points[i] = [ai, bi] represents that a point exists at (ai, bi). A point is valid if it shares the same x-coordinate or the same y-coordinate as your location.

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12. Integer to Roman

2021-07-20

Problem description:

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M.

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156. Binary Tree Upside Down

2021-07-19

Problem description:

Given the root of a binary tree, turn the tree upside down and return the new root.

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101. Symmetric Tree

2021-07-19

Problem description:

Given the root of a binary tree, check whether it is a mirror of itself (i.e., symmetric around its center).

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715. Range Module

2021-07-18

Problem description:

A Range Module is a module that tracks ranges of numbers. Design a data structure to track the ranges represented as half-open intervals and query about them.

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730. Count Different Palindromic Subsequences

2021-07-17

Problem description:

Given a string s, return the number of different non-empty palindromic subsequences in s. Since the answer may be very large, return it modulo 109 + 7.

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450. Delete Node in a BST

2021-07-16

Problem description:

Given a root node reference of a BST and a key, delete the node with the given key in the BST. Return the root node reference (possibly updated) of the BST.

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545. Boundary of Binary Tree

2021-07-14

Problem description:

The boundary of a binary tree is the concatenation of the root, the left boundary, the leaves ordered from left-to-right, and the reverse order of the right boundary.

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460. LFU Cache

2021-07-14

Problem description:

Design and implement a data structure for a Least Frequently Used (LFU) cache.

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373. Find K Pairs with Smallest Sums

2021-07-13

Problem description:

You are given two integer arrays nums1 and nums2 sorted in ascending order and an integer k.

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