744. Find Smallest Letter Greater Than Target

2021-07-12

Problem description:

Given a characters array letters that is sorted in non-decreasing order and a character target, return the smallest character in the array that is larger than target.

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361. Bomb Enemy

2021-07-11

Problem description:

Given an m x n matrix grid where each cell is either a wall 'W', an enemy 'E' or empty '0', return the maximum enemies you can kill using one bomb. You can only place the bomb in an empty cell.

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465. Optimal Account Balancing

2021-07-10

Problem description:

You are given an array of transactions transactions where transactions[i] = [fromi, toi, amounti] indicates that the person with ID = fromi gave amounti $ to the person with ID = toi.

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432. All O(1) Data Structure

2021-07-09

Problem description:

Design a data structure to store the strings’ count with the ability to return the strings with minimum and maximum counts.

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36. Valid Sudoku

2021-07-08

Problem description:

Determine if a 9 x 9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules:

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671. Second Minimum Node In a Binary Tree

2021-07-07

Problem description:

Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node’s value is the smaller value among its two sub-nodes. More formally, the property root.val = min(root.left.val, root.right.val) always holds.

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367. Valid Perfect Square

2021-07-06

Problem description:

Given a positive integer num, write a function which returns True if num is a perfect square else False.

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802. Find Eventual Safe States

2021-07-04

Problem description:

We start at some node in a directed graph, and every turn, we walk along a directed edge of the graph. If we reach a terminal node (that is, it has no outgoing directed edges), we stop.

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841. Keys and Rooms

2021-07-03

Problem description:

There are N rooms and you start in room 0. Each room has a distinct number in 0, 1, 2, ..., N-1, and each room may have some keys to access the next room.

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265. Paint House II

2021-07-02

Problem description:

There are a row of n houses, each house can be painted with one of the k colors. The cost of painting each house with a certain color is different. You have to paint all the houses such that no two adjacent houses have the same color.

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